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Glossary of Human Performance Terms

Definitions Collected and Organized By:

 Jonathon Janz MS, CSCS, USAW Level I

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z References

1 RM – One Rep Maximum

The maximum amount of weight a subject can lift for a particular exercise (Baechle & Earle, 2000)



The area located in the center of the sarcomere containing both actin and myosin (Foss & Keteyian, 1998)

Abduct, Abduction

             To move away from the midline of the body (Marieb, 1998)


Stable characteristics or traits, genetically defined and unmodifiable by practice or experience, that underlie certain skilled performances (Schmidt & Lee, 1999)

Absolute Constant Error ( |CE| )

The absolute value of CE for each subject; a measure of amount of bias without respect to direction (Schmidt & Lee, 1999)

Absolute Error (AE)

The average absolute deviation of a set of scores from a target value; a measure of overall error (Schmidt & Lee, 1999)

Absolute Frequency of Knowledge of Results

            The absolute number of KRs given in a sequence of trials (Schmidt & Lee, 1999)

Absolute Retention

A measure of retention based on the level of performance on the retention test (Schmidt & Lee, 1999)

Absolute Strength

            Maximum involuntary strength (Siff, 2003)


Change in velocity per unit time (Baechle & Earle, 2000)

Acceleration of Specific Adaptation

Idea that specific adaptation should be accelerated by advancing the stage when maximum sports proficiency is expected to be produced by the current training regime (Siff, 2003)

Acceleration Strength

The ability over time to quickly achieve maximal external force while developing muscle tension isometrically or at the beginning of a dynamic action (Siff, 2003)

Accelerated Powermetrics

The use of elastic bands or other means to provide added resistance during the eccentric and/or concentric phases of a movement (Siff, 2003)


Short-term changes that occur within the body which lessen the physiological strain that develops in response to changes in climate (Foss & Keteyian, 1998)


Certain physiological adjustments brought forth through continued exposure to a different climate (Foss & Keteyian, 1998)

Accommodating Resistance

The presence of a counterforce which controls the speed of contraction during isokinetic testing (Foss & Keteyian, 1998)

Accumulated Feedback

Information presented after a series of movements that represents a summary of those performances (Schmidt & Lee, 1999)

Acetyl Coenzyme A (Acetyl CoA)

The compound that forms the common entry point into the Krebs cycle for the oxidation of carbohydrate and fat (Wilmore & Costill, 2004)

Acetylcholine (ACh)

A chemical found in the body which is involved in several important physiological functions such as nerve impulse transmission from one nerve fiber to another across a synapse (Foss & Keteyian, 1998)

Achievement Motivation

Relates to the athlete’s wish to engage in competition or social comparison (Baechle & Earle, 2000)


A condition of low alkali reserve (bicarbonate) in the blood and other body fluids, which is sometimes associated with an increase in H-ion concentration (acid) and a decrease in blood pH below normal levels (Foss & Keteyian, 1998)


            A muscle protein involved in contraction (Marieb, 1998)

Action-Centered Interference

A view of attention that localizes interference effects at the response-selection stage (Schmidt & Lee, 1999)

Action Potential

Electrical activity developed in a muscle or nerve cell during depolarization (activity) (Foss & Keteyian, 1998)

Active Stabilizers

            See Stabilizers (Siff, 2003)

Active Transport

The movement of substances against their concentration gradients by utilizing metabolic energy (Foss & Keteyian, 1998)


A protein complex formed from actin and myosin when myosin cross-bridges bond chemically with actin filaments (Foss & Keteyian, 1998)

Acute Muscle Soreness

Pain occurring during or immediately following performance of high-intensity exercise; associated with inadequate flow of blood (Foss & Keteyian, 1998)

Acute Response

            A physiological response to a single bout of exercise (Wilmore & Costill, 2004)

Adams’s Theory

A closed-loop theory of motor learning proposed by Adams (1971), focusing heavily on the learning of slow positioning movements (Schmidt & Lee, 1999)

Adaptive Reconstruction

The phenomenon in which the body adapts to stress, such as that imposed by training loads; similar to supercompensation (Siff, 2003)


            Natural substances used to facilitate adaptation to stress (Siff, 2003)

Adduct, Adduction

            To move toward the midline of the body (Marieb, 1998)


One of the two major purines found in both RNA and DNA; also used as an aromatic base that when linked to ribose forms adenosine, the foundation for ATP, ADP, and AMP (Foss & Keteyian, 1998), (Marieb, 1998)


The anterior lobe of the pituitary gland which secretes six major hormones (Foss & Keteyian, 1998), (Marieb, 1998)


The molecular foundation for ATP, ADP, and AMP, consisting of a five-carbon sugar (ribose) attached to an aromatic base (adenine) (Foss & Keteyian, 1998)

Adenosine Diphosphate (ADP)

An organic molecule that forms ATP when combined with inorganic phosphate (Pi) (Foss & Keteyian, 1998), (Marieb, 1998)

Adenosine Monophosphate (AMP)

An organic molecule formed by the hydrolysis of the two phosphate groups found in Adenosine Triphophate (ATP) (Baechle & Earle, 2000)

Adenosine Triphosphatase (ATPase)

An enzyme that splits the last phosphate group off ATP, releasing a large amount of energy and reducing the ATP to ADP and P (Wilmore & Costill, 2004)

Adenosine Triphosphate (ATP)

An organic molecule formed with the energy released from flood and stored in all body cells, particularly the muscles; the breakdown of ATP provides the cells with their sole source of energy for work (Foss & Keteyian, 1998), (Marieb, 1998)


            A fat cell; a cell that provides the storage of fat (Foss & Keteyian, 1998)

Adipose Tissue

            Fat tissue (Marieb, 1998)

Adjacent-Trial Effect

With intertrial correlation matrices, the tendency for the correlations between adjacent trials to increase with practice (Schmidt & Lee, 1999)


            The period between childhood and adulthood (Baechle & Earle, 2000)

Adrenal Cortex

The outer part of the adrenal gland that secretes over forty different hormones known as steroids (categorized as mineralocorticordoids, glucocorticoids, and androgens) (Foss & Keteyian, 1998)

Adrenal Medulla

The inner part of the adrenal gland that serves as an extension of the sympathetic nervous system; secretes epinephrine and norephinephrine (Foss & Keteyian, 1998)

Adrenocorticotrophic Hormone (ACTH or Corticotropin)

An andrenohypophysis hormone that stimulates the production and release of glucocorticoid hormone from the adrenal cortex (Foss & Keteyian, 1998), (Marieb, 1998)

Aerobic Endurance

The amount of time a muscle can continue to remain active using aerobic pathways (Marieb, 1998)

Aerobic Respiration (Aerobic Metabolism)

Respiration in which oxygen is consumed and glucose is completely broken down; water, carbon dioxide, and large amounts of ATP are the final products (Marieb, 1998)

Aerobic Power

The maximal rate at which a person can consume oxygen during the performance of a maximum effort, exhaustive exercise; an indicator of cardiovascular fitness (Foss & Keteyian, 1998)

Aerobic System

Denotes the entire series of biochemical reactions and pathways where ATP can be synthesized from food only in the presence of oxygen; includes aerobic glycolysis, the Krebs Cycle, and Electron Transport Chain (Foss & Keteyian, 1998)


            Carrying to or toward a center (Marieb, 1998)

Afferent (Sensory) Nerve

A nerve that contains the processes of sensory neurons and carries nerve impulses to the central nervous system (Marieb, 1998)

Afferent (Sensory) Neuron

A nerve cell that carries impulses toward the central nervous system; initiates impulses following receptor stimulation (Marieb, 1998)


A muscle that is primarily responsible for effecting a specific movement; a prime mover (Marieb, 1998)

Air Plethysmography

A procedure for assessing body composition by using air displacement to measure body volume, allowing the calculation of body density (Wilmore & Costill, 2004)

Alactacid Oxygen Debt

A portion of the recovery oxygen that is used to resynthesize and restore ATP and phosphocreatine (PC) in muscle post exercise; the rapid recovery phase (Foss & Keteyian, 1998)


A mineralocorticoid produced by the adrenal cortex that regulates sodium ion reabsorption (Foss & Keteyian, 1998), (Marieb, 1998)

Alkali Reserve

The amount of bicarbonate (base) available in the body for buffering acid (Foss & Keteyian, 1998)


            A base; opposite of acid (Foss & Keteyian, 1998)


A state of abnormally low hydrogen ion (acid) concentration in the extracellular fluid (Marieb, 1998)

All or None Law

A stimulated muscle or nerve fiber contracts or propagates an impulse either completely or not at all; once activated, a maximal response occurs (no gradation of action) (Foss & Keteyian, 1998)


            See Auxotonic (Siff, 2003)

Allosteric Binding Site

A receptor at which substances other than hormones can enhance or reduce the cellular response to the primary hormone (Baechle & Earle, 2000)

Alpha (a) Helix

The most common type of secondary structure of the amino acid chain in proteins (Marieb, 1998)

Alpha-Gamma (a-g) Coactivation

The firing of both alpha and gamma motor neurons to the same muscle at nearly the same time producing voluntary contraction (Foss & Keteyian, 1998)

Alpha (a) Motor Neuron

A type of efferent nerve cell that innervates extrafusal muscle fibers; large efferent neurons responsible for innervation of the extrafusal fibers of the skeletal musculature (Foss & Keteyian, 1998) (Schmidt & Lee, 1999)

Alternating Sets

Training involving alternating sets of exercises for different regions of the body to achieve specific training goals (Siff, 2003)

Alveolar-Capillary Membrane

The thin layer of tissue dividing the alveoli and the pulmonary capillaries where gas exchange occurs in the lungs (Foss & Keteyian, 1998)

Alveolar (acinar) Gland

            A gland containing secretory cells that form small, flask-like sacs (Marieb, 1998)

Alveolar Pressure

The pressure inside the alveoli when the glottis is open and no air is flowing into our out of the lungs (Baechle & Earle, 2000)

Alveolar Ventilation Rate (AVR)

An index of respiratory efficiency; a measurement of the volume of air wasted and flow of fresh gases in and out of the alveoli (Marieb, 1998)


            A single, microscopic air sac in the lung (Marieb, 1998)


            The surrounding environment (Foss & Keteyian, 1998)

Amino Acid Deamination

Metabolic process where the nitrogen containing amino radical (NH2) is removed from the amino acid molecule (Foss & Keteyian, 1998)         

Amino Acid

An organic compound containing nitrogen, carbon, hydrogen, and oxygen.  It is the building block of protein (Marieb, 1998)


Stoppage of menstrual cycles; not uncommon in female athletes practicing rigorous endurance training or severely restricting their body weight; often preceded by irregular menses (Foss & Keteyian, 1998)


In plyometrics, the phase occurring when the kinetic energy from a prior movement produces a powerful myotatic stretch reflex which leads to eccentric muscle action accompanied by explosive isometric contraction and stretching of the series elastic component of the muscle complex (Siff, 2003)

Ammonia (NH3)

Common waste product of protein breakdown in the body; a colorless volatile gas, very soluable in water and capable of forming a weak base; a protein acceptor (Marieb, 1998)


            A slightly movable joint (Marieb, 1998)


A synthetically structured drug closely related to epinephrine; it produces stimulation of the central nervous system (Foss & Keteyian, 1998)

Anabolic-Androgenic Steroid

A compound that promotes tissue-building and male-like bodily characteristics; it is conducive to the constructive (building up) process of metabolism (Foss & Keteyian, 1998)

Anabolism (Anabolic)

Energy-requiring building phase of metabolism in which simpler substances are combined to form more complex substances; protein building (Foss & Keteyian, 1998), (Marieb, 1998)


In the absence of oxygen; not requiring oxygen (Foss & Keteyian, 1998), (Marieb, 1998)

Anaerobic Glycolysis

The incomplete chemical breakdown of carbohydrate; the anaerobic reactions in this breakdown release energy for the manufacture of ATP as they produce lactic acid (anaerobic glycolysis is known as the lactic acid system); energy-yielding conversion of glucose to lactic acid in various tissues, notably muscle, when sufficient oxygen is not available (Foss & Keteyian, 1998), (Marieb, 1998)

Anaerobic Power

The development of maximal or peak power during exertion; measured as work (force in kg x distance in meters) expressed per unit of time (min) (Foss & Keteyian, 1998)

Anaerobic Threshold

That intensity of work load or oxygen consumption at which anaerobic metabolism is accelerated; the point at which muscle metabolism converts to anaerobic glycolysis (Foss & Keteyian, 1998), (Marieb, 1998)

Analytical-Synthetic Method

The qualities of performance should be developed separately with the appropriate means and then integrated into the special exercises; the breaking down of performance into its respective parts for training purposes, then assembling the components into an integrated whole (Siff, 2003)

Anatomical Dead Space (Vd)

That volume of fresh air that remains in the respiratory passages (nose, mouth, pharynx, larynx, bronchi, and bronchioles) and does not participate in gaseous exchange (Foss & Keteyian, 1998)

Anatomical Position

The body is erect, the arms are down at the sides, and the palms face forward (Baechle & Earle, 2000)


Encompasses the study of components that make up the musculoskeletal “machine” (Baechle & Earle, 2000)


Reduced oxygen-carrying ability of blood resulting from too few erythrocytes or abnormal hemoglobin (Marieb, 1998)

Angiotensin Converting Enzyme (ACE)

            An enzyme that converts Angiotensin I to Angiotensin II (Wilmore & Costill, 2004)

Angle of Pennation

The angle between the muscle fibers and an imaginary line between the muscle’s origin and insertion (Baechle & Earle, 2000)

Angular Displacement

            The angle through which an object rotates (Baechle & Earle, 2000)

Angular Kinetics

            The branch of mechanics that deals with the causes of rotations (Hamill & Knutzen 2003)

Angular Momentum

The quantity of angular motion determined by the product of the object’s angular velocity and its moment of inertia (Hamill & Knutzen 2003)

Angular Power

The time rate of change of angular work determined by the product of the torque and the angular velocity (Hamill & Knutzen 2003)

Angular Velocity

            An object’s rotational speed, measured in radians per second (Baechle & Earle, 2000)

Angular Work

The product of torque applied to an object and the angular distance over which the torque is applied (Hamill & Knutzen 2003)

Annulospiral Nerve

Sensory (afferent) nerve from central region of muscle spindle; sends impulses to CNS with whole muscle stretch or intrafusal fiber shortening (Foss & Keteyian, 1998)

Anorexia Nervosa

A clinical disorder of eating associated with loss of appetite, distorted body image, and an intense fear of fatness or weight gain (Foss & Keteyian, 1998)


            Muscle that reverses, opposes, the action of another muscle (Marieb, 1998)


The measurement of the size and proportions of the human body (Foss & Keteyian, 1998)

Antidiuretic Hormone (ADH, also called Vasopressin)

A hormone secreted by the posterior lobe of the pituitary gland that functions mainly to promote water reabsorption from the collecting tubules of the kidney (Foss & Keteyian, 1998)


Substances that provide elections that reduce free radicals associated with other molecules (Foss & Keteyian, 1998)


A coordination pattern in which two movement components oscillate in 180º relative phase (Schmidt & Lee, 1999)


A subjective experience of apprehension and uncertainty accompanied by elevated autonomic

and voluntary neural outflow and increased endocrine activity (Baechle & Earle, 2000)

Aortic Valve

Semilunar valve between the left ventricle and the aorta; prevents the backflow from the aorta into the ventricles during ventricular relaxation (diastole) (Baechle & Earle, 2000)

Apocrine Gland

The less numerous type of sweat gland; produces a secretion containing water, salts, proteins, and fatty acids (Marieb, 1998)


            The protein portion of an enzyme (Marieb, 1998)


Fibrous or membranous sheet connecting a muscle and the part it moves (Marieb, 1998)


            Relating to the limbs; one of the two major divisions of the body (Marieb, 1998)


            Pertaining to water (Foss & Keteyian, 1998)


The intensity dimension of behavior and physiology; an internal state of alertness or excitement (Baechle & Earle, 2000) (Schmidt & Lee, 1999)


            Irregular heart rhythm caused by defects in the intrinsic conduction system (Marieb, 1998)

Arterial Mixed Venous Oxygen Difference (a-VO2 diff)

The difference between the oxygen content of arterial and mixed venous blood (Foss & Keteyian, 1998)


Blood vessels that conduct blood away from the heart and into the circulation (Marieb, 1998)


            A minute artery (Marieb, 1998)


Any of a number of proliferative and degenerative changes in the arteries leading to their decreased elasticity (Marieb, 1998)


            Inflammation of the joints (Marieb, 1998)

Arthroscopic surgery

Procedure enabling a surgeon to repair the interior of a joint through a small incision (Marieb, 1998)

Articular Capsule

Double-layered capsule composed of an outer fibrous capsule lined by synovial membrane; encloses the joint cavity of a synovial joint (Marieb, 1998)

Articular Cartilage

            Hyaline cartilage covering bone ends at movable joints (Marieb, 1998)


            The junction of two or more bones (Marieb, 1998)

Assistant Mover

            Muscles that play a secondary role to that of a prime mover in a particular action (Siff, 2003)


A strategy in which an athlete will carefully monitor their performance and perceived physiological state while engaged in activity (Baechle & Earle, 2000)

Associative Phase

The second of three phases of learning proposed by Fitts, in which learners establish motor patterns (Schmidt & Lee, 1999)

Associative System

            A system in which operations follow this law: A*(B*C) = (A*B)*C (Siff, 2003)


            Disruption of muscle coordination resulting in inaccurate movements (Marieb, 1998)


A disease of the arteries in which lipid (fat) material and cholesterol accumulate on the inside walls of the arteries; changes in the walls of large arteries consisting of lipid deposits on the artery walls; the early stage of arteriosclerosis (Foss & Keteyian, 1998), (Marieb, 1998)

Athlete’s Heart

A nonpathological enlarged heart, often found in endurance athletes, that results primarily from left ventricular hypertrophy in response to training (Wilmore & Costill, 2004)


See Adenosine Triphosphate


            An enzyme that facilitates the breakdown of ATP (Foss & Keteyian, 1998)

ATP-PC System

An anaerobic energy system in which ATP is manufactured when phosphocreatine (PC) is broken down; this system represents the most rapidly available source of ATP for use by muscle; activities performed at maximum intensity for a period of 10 seconds or less derive energy (ATP) from this system (Foss & Keteyian, 1998)

Atrioventricular (AV) Bundle

Part of the heart conduction system that conducts the impulse to the ventricles (Baechle & Earle, 2000)

Atrioventricular (AV) Node

Part of the heart conduction system that delays the impulse slightly before it passes into the ventricles (Baechle & Earle, 2000)

Atrioventricular (AV) Valves

Prevent the flow of blood from the ventricles back into the atria during ventricular contraction (Baechle & Earle, 2000)


Two superior chambers of the heart; function primarily as blood reservoirs, delivering blood into the right and left ventricles (Baechle & Earle, 2000)


A reduction in the cross-sectional area of muscle, muscle fibers, or other tissues due to injury, disuse, disease, immobilization, or similar factors; reduction in size or wasting away of an organ or cell resulting from disease or lack of use (Foss & Keteyian, 1998), (Marieb, 1998)


The athlete’s ability to focus; the processing of those environmental cues that come to awareness; a concept that describes limitations in the processing of information (Baechle & Earle, 2000) (Schmidt & Lee, 1999)

Augmented Feedback

Feedback that is added to the feedback typically received in the task (also called extrinsic feedback) (Schmidt & Lee, 1999)

Autogenic Inhibition

Reflex inhibition of a motor neuron in response to excessive tension in the muscle fibers it supplies, as monitored by the Golgi tendon organs (Wilmore & Costill, 2004)

Autogenic Training

An athlete visualizes him or herself in action, feeling all of the muscular tensions and movements, as well as the physiological and emotional changes actually occurring in competition; Refers to shifting autonomic neural processes from sympathetic to parasympathetic dominance (Baechle & Earle, 2000) (Siff, 2003)

Automatic Processing

Information processing that is relatively fast, that is done in parallel with other processes, and that requires minimal effort (compare with controlled processing ) (Schmidt & Lee, 1999)

Autonomic Nervous System (ANS)

A self-controlled system that helps to control activities such as those involving movement and secretion by the visceral organs, urinary output, body temperature, heart rate, adrenal secretion, and blood pressure; efferent division of the peripheral nervous system that innervates cardiac and smooth muscles and glands; also called the involuntary or visceral motor system (Foss & Keteyian, 1998), (Marieb, 1998)

Autonomous Phase

The third of three phases of learned proposed by Fitts, in which learners have greatly reduced the attention demands of the task (Schmidt & Lee, 1999)


Local control of blood distribution (through vasodilation) in response to a tissue’s changing needs (Wilmore & Costill, 2004)


            Muscle action involving changes in muscle tension and length (Siff, 2003)

Average Knowledge of Results

A type of summary knowledge of results method that presents the results of two or more trials as a statistical average (Schmidt & Lee, 1999)

Average Velocity

The speed of a movement, or the movement distance divided by the movement time (Schmidt & Lee, 1999)


Relating to the head, neck, and trunk; one of the two major divisions of the body (Marieb, 1998)


A nerve fiber; neuron process that carries impulses away from the nerve cell body; efferent process; the conduction portion of a nerve cell (Foss & Keteyian, 1998), (Marieb, 1998)

Axon Hillock

A part of the neuron, between the cell body and the axon, that controls traffic down the axon through summation of excitatory and inhibitory postsynaptic potentials (Wilmore & Costill, 2004)

Axon Terminal

One of numerous branched endings of an axon; also known as a terminal fibril (Wilmore & Costill, 2004)



            The ability of an individual to assume and maintain a stable position (Hamill & Knutzen 2003)


Bursts of muscular activity followed by phases of relaxation during which the motion continues due to stored limb momentum (Siff, 2003)

Ballistic Stretching

Imposes passive momentum to exceed static range of motion on the relaxed or contracted muscle complex; may be done slowly or rapidly (Siff, 2003)

Bandwidth Knowledge of Results

Tolerance limits on errors that define when to provide qualitative or quantitative knowledge of results (Schmidt & Lee, 1999)


Receptors primarily located in the walls of the carotid arteries and the aortic arch that are sensitive to transluminal stretch; when activated, they increase the afferent firing rate to the cardiorespiratory center of the medulla; pressoreceptor that is stimulated by pressure changes (Foss & Keteyian, 1998), (Marieb, 1998)

Basal Metabolic Rate (BMR)

Rate at which energy is expended (heat produced) by the body per unit time under controlled (basal) conditions (12 hours after a meal at rest) (Marieb, 1998)

Basal Ganglia (Nuclei)

Subcortical portion of the brain that, along with the thalamus, provides an information loop back to the premotor cortex to assist in the selection and initiation of chosen movements; gray matter areas located deep within the white matter of the cerebral hemispheres (Foss & Keteyian, 1998), (Marieb, 1998)


            A substance capable of binding with hydrogen ions; a proton acceptor (Marieb, 1998)


Beta-Blockers (b-Blockers)

A class of drugs that block transmission of neural impulses from the sympathetic nervous system, proposed to have Ergogenic properties (Wilmore & Costill, 2004)

Beta-Cells (b-Cells)

            Cells in the islets of Langerhans in the pancreas that secrete insulin (Wilmore & Costill, 2004)

Beta-Oxidation (b-Oxidation)

The series of reactions by which fat is broken down from long carbon chains to two carbon units in preparation for entry into the Krebs Cycle (Foss & Keteyian, 1998)

Biaxial Joint

Joints that allow movement about two perpendicular axes; the ankle and wrist are examples (Baechle & Earle, 2000)

Bicarbonate Ion (HCO3-)

            A by-product of the dissociation (ionizing) of carbonic acid (Foss & Keteyian, 1998)

Bicarbonate Loading

Ingesting biocarbonate to elevate blood pH with hopes of delaying fatigue by increasing the capacity to buffer acids (Wilmore & Costill, 2004)


            Two-headed, especially applied to certain muscles (Marieb, 1998)

Bicuspid Valve

Prevent the flow of blood from the ventricles back into the atria during ventricular contraction; also known as the mitral valve (Baechle & Earle, 2000)

Bilateral Deficit

The force produced with bilateral contractions is usually less that the sum of the forces produced individually by the left and right limbs (Siff, 2003)

Binge Eating Disorder

An eating disorder in which a person will ingest a large amount of food without purging (Baechle & Earle, 2000)

Bioelectric Impedance

A procedure for assessing body composition in which an electrical current is passed through the body; the resistance to current flow through the tissues reflects the relative amount of fat present (Wilmore & Costill, 2004)


            The study of energy transformation in living organisms (Foss & Keteyian, 1998)


Training that provides an awareness of visceral activities; enables an element of voluntary control over autonomic body functions (Marieb, 1998)

Biogenic Amines

            Class of neurotransmitters, including catecholamines and indolamines (Marieb, 1998)

Biological Age

Age measured in terms of skeletal age, somatic maturity, or sexual maturation (Baechle & Earle, 2000)

Biologically Active Substances

            See Adaptogens (Siff, 2003)


Study of the mechanisms through which the components of the anatomy interact to create movement (Baechle & Earle, 2000)

Biomechanical Efficiency

Relates to the genetic factors such as the leverage characteristics of the body, the relative strengths of the different muscle groups controlling the movement of each limb, and the neuromuscular efficiency which orchestrates all movement patterns of the body (Siff, 2003)


            The removal and examination of tissue from the living body (Marieb, 1998).


The amount of information required to reduce the original amount of uncertainty by half (Schmidt & Lee, 1999)

Black Globe Thermometer

An ordinary thermometer placed in a black globe; the black bulb temperature measures radiant energy or solar radiation and is one of three temperatures used to compute the WBGT index (Foss & Keteyian, 1998)

Blocked Practice

A practice sequence in which all of the trials on one tasks are done together, uninterrupted by practice on any of the other tasks; low contextual interference (Schmidt & Lee, 1999)

Blood Doping

The removal and subsequent reinfusion of blood, undertaken to temporarily increase oxygen-carrying red blood cells (Foss & Keteyian, 1998)

Blood Glucose

Simple form of sugar (carbohydrate) circulating in blood; levels are regulated mainly through the glycogen stored in the liver (Foss & Keteyian, 1998)

Blood Lipids

            Blood-borne fats, such as triglycerides and cholesterol (Wilmore & Costill, 2004)

Blood Pressure

The force per unit area exerted by the blood against the inside walls of an artery; the driving force that moves blood through the circulatory system; differences in blood pressure between different areas of the circulation provide the driving force for blood circulation (Foss & Keteyian, 1998), (Marieb, 1998)

Body Composition

            The chemical composition of the body (Wilmore & Costill, 2004)

Body Density

            Body weight divided by body volume (Wilmore & Costill, 2004)

Body Mass Index (BMI)

The preferred body compostion assessment for obese individuals, as skinfold assessment becomes inaccurate because of the size of the skinfold and the lack of standardized formulas for obese adults; calculated as weight in kilograms divided by height squared in meters (Baechle & Earle, 2000)

Bone Matrix

Proteins, including collagen molecules, which form a meshwork between bone cells (Baechle & Earle, 2000)

Bone Mineral Density

            The quantity of mineral deposited in a given area of bone (Baechle & Earle, 2000)

Bone Modeling

The process initiated by mechanical loading in which osteoblasts migrate to the bone surface and produce the bone matrix (Baechle & Earle, 2000)

Bone Tissue

            A connective tissue that forms the bony skeleton (Marieb, 1998)

Bone Remodeling

Process Involving bone formation and destruction in response to hormonal and mechanical factors (Marieb, 1998)

Bone Resorption

The removal of osseous tissue; part of the continuous bone remodeling process (Marieb, 1998)

Borg Rate of Perceived Exertion Scale (Borg RPE scale)

            A numerical scale for rating perceived exertion (Wilmore & Costill, 2004)

Boyle’s Law

The volume occupied by a gas (at constant temperature) is reduced or expanded in direct proportion to the pressure placed around it; very important to underwater diving; states that when the temperature is constant, the pressure of a gas varies inversely with its volume (Foss & Keteyian 1998), (Marieb, 1998)

Bracketing Technique

An athlete performs the sport movement with lighter-than-normal and heavier-than-normal implements; it is another form of acceleration training (Baechle & Earle, 2000)


            A heart rate less than 60 beats per minute (Foss & Keteyian, 1998)

Branched-Chain Amino Acid

Major amino acids oxidized in skeletal muscle; include leucine, isoleucine, valine, and sometimes alanine, aspartate, and glutamate (Baechle & Earle, 2000)

Brief Maximal Tension Method

Method that develops the ability to concentrate neuromuscular effort and yields a larger training effect than the progressive resistance method for developing maximum strength and the ability to display it quickly (Siff, 2003)


            The branching air passageways inside the lungs (Marieb, 1998)


            One of the two large branches of the trachea that leads to the lungs (Marieb, 1998)


Any substance in a fluid that lessens the change in hydrogen ion (H+) concentration which otherwise would occur by adding acids or bases; chemical substance or system that minimizes changes in pH by releasing or binding hydrogen ions (Foss & Keteyian, 1998), (Marieb, 1998)

Bulimia Nervosa

Recurrent binge eating followed by purging (self-vomiting, misuse of laxatives, diuretics, or enemas) or by fasting/excessive exercise (Baechle & Earle, 2000)


A fibrous sac lined with synovial membrane and containing synovial fluid; occurs between bones and muscle tendons (or other structures), where it acts to decrease friction during movement (Marieb, 1998)


            Inflammation of the bursa (Marieb, 1998)


A central nervous system stimulant believed by some athletes to have ergogenic properties (Wilmore & Costill, 2004)

Calcaneal tendon

Tendon that attaches the calf muscles to the heelbone (calcaneus); also called the Achilles tendon (Marieb, 1998)


A hormone secreted by the thyroid gland that causes a decrease in the blood calcium level; it is thought that calcitonin may also be secreted from the parathyroid glands; also called thyrocalcitonin (Foss & Keteyian, 1998), (Marieb, 1998)


Localized thickening of skin epidermis resulting from physical trauma; repair tissue (fibrous or bony) formed at a fracture site (Marieb, 1998)


A unit of work or energy equal to the amount of heat required to raise the temperature of one gram of water 1º C; energy exchanges associated with biochemical reactions are usually reported in kilocalories (1 kcal = 1000 cal) or large calories (Cal) (Foss & Keteyian, 1998), (Marieb, 1998)


Measures heat production from oxidized food stuffs (bomb-type) or heat production from the human body (line-in-type) (Foss & Keteyian, 1998)

Capacity Interference

            Interference between tasks caused by limitations in attention (Schmidt & Lee, 1999)


A fine network of small vessels located between arteries and veins where exchanges between tissue and blood occur (Foss & Keteyian, 1998)

Capillary to Fiber Ratio

            The number of capillaries per muscle fiber (Wilmore & Costill, 2004)

Carbamino Compounds

The end product obtained from the chemical combination of plasma proteins and/or hemoglobin (Hgb) and carbon dioxide (CO2) (Foss & Keteyian, 1998)


A carbamino compound formed in the red blood cells when CO2 reacts with Hgb (Foss & Keteyian, 1998)


Any of a group of chemical compounds, including sugars, starches, and cellulose; contains carbon, hydrogen, and oxygen only; organic compound composed of carbon, hydrogen, and oxygen including sugars, starches, and cellulose (Foss & Keteyian, 1998), (Marieb, 1998)

Carbohydrate Loading

A technique used to enhance muscle glycogen prior to long-term aerobic endurance exercise; the most effective regiment with the fewest side effects is three days of a high-carbohydrate diet in concert with tapering exercise the week before the competition and complete rest the day before the event (Baechle & Earle, 2000)

Carbonic Acid-Bicarbonate System

            Chemical buffer system that helps maintain pH homeostasis of the blood (Marieb, 1998)

Carbonic Anhydrase

An enzyme that speeds up the reaction of carbon dioxide (CO2) with water (H2O) (Foss & Keteyian, 1998)

Cardiac Cycle

Contraction (systole) and relaxation (distole) of the heart; sequence of events encompassing one complete contraction and relaxation of the atria and ventricles of the heart (Foss & Keteyian, 1998), (Marieb, 1998)

Cardiac Hypertrophy

Enlargement of the heart by increases in muscle wall thickness or chamber size or both (Wilmore & Costill, 2004)

Cardiac Muscle

            Specialized muscle of the heart (Marieb, 1998)

Cardiac Output (Q)

The amount of blood pumped by the heart in one minute; the product of the stroke volume and the heart rate; Amount of blood pumped out of a ventricle in one minute (Foss & Keteyian, 1998), (Marieb, 1998)

Cardiac Reserve

            The difference between resting and maximal cardiac output (Marieb, 1998)

Cardiogenic Shock

Pump failure; the heart is so inefficient that it cannot sustain adequate circulation (Marieb, 1998)

Cardiorespiratory Endurance

The ability of the lungs and heart to take in and transport adequate amounts of oxygen to the working muscles, allowing activities that involve large muscle masses (e.g., running, swimming, bicycling) to be performed over long periods of time (Foss & Keteyian, 1998) 

Cardiovascular Deconditioning

A decrease in the cardiovascular system’s ability to deliver sufficient oxygen and nutrients (Wilmore & Costill, 2004)

Cardiovascular Drift

A compensatory increase in heart rate that usually occurs during prolonged endurance exercise in response to a decrease in stroke volume; cardiac output is maintained as a result (Foss & Keteyian, 1998)

Cardiovascular System

Organ system which distributes the blood to deliver nutrients and remove wastes (Marieb, 1998)

Carotid Body

A receptor in the common carotid artery sensitive to changing oxygen, carbon dioxide, and pH levels of the blood (Marieb, 1998)

Carotid Sinus

A dialation of a common carotid artery; involved in regulation of systemic blood pressure (Marieb, 1998)


            White, semiopaque connective tissue (Marieb, 1998)

Cartilage Bone (Endochondral Bone)

            Bone formed by the calcification of hyaline cartilage structures (Marieb, 1998)

Cartilage Matrix

The internal environment of the cartilage tissue, within which the collagen fibers traverse (Baechle & Earle, 2000)

Cartilaginous Joints

            Bones united by cartilage; no joint cavity is present (Marieb, 1998)

Catabolic Hormone

Hormones that degrade cell proteins to support glucose synthesis (Baechle & Earle, 2000)

Catabolism (Catabolic)

Process in which living cells break down substances into simpler substances (Marieb, 1998)


Substance that increases the rate of a chemical reaction without itself becoming chemically changes or part of the product (Marieb, 1998)

Catastrophe Hypothesis

A nonlinear description of the nonlinear relationship between arousal and performance (Schmidt & Lee, 1999)

Catastrophic Theory

The theory that holds that increases in physiological arousal occur in the presence of cognitive anxiety until a point at which a sudden drop in performance occurs (Baechle & Earle, 2000)


            Epinephrine and norepinephrine (Marieb, 1998)


            Literally, toward the tail; in humans, the inferior portion of the anatomy (Marieb, 1998)

Ceiling Effect

A limitation, imposed either by the scoring system or by physiological-psychological sources, that places a maximum on the score that a performer can achieve in a task (Schmidt & Lee, 1999)

Cell Turnover

            The constant breakdown and regeneration of cells in the body (Baechle & Earle, 2000)

Cellular Respiration

            Metabolic processes in which ATP is produced (Marieb, 1998)

Center of Gravity

The point at which all of the body’s mass seems to be concentrated; the balance point of the body; the point about which the sum of the torques equals zero (Hamill & Knutzen 2003)

Center of Mass

A balance point of a body; the point about which all of the mass particles of the body are evenly distributed (Hamill & Knutzen 2003)

Central (Haversian) Canal

The canal in the center of each osteon that contains minute blood vessels and nerve fibers that serve the needs of the osteocytes (Marieb, 1998)

Central Command

Neurons originating in the motor cortex that influence the cardiorespiratory (ventilation and cardiovascular) center of the medulla on their way to initiate skeletal muscle action (Foss & Keteyian, 1998)

Central Nervous System (CNS)

            Brain and spinal cord (Marieb, 1998)

Central Neural Fatigue

Decrease in muscle force attributable to a decline in motoneuronal output (Foss & Keteyian, 1998)

Central Pattern Generators

Mechanisms in the spinal cord capable of providing oscillatory behavior thought to be involved in the control of locomotion and other tasks (Schmidt & Lee, 1999)


Brain region most involved in producing smooth, coordinated skeletal muscle activity (Marieb, 1998)

Cerebral Cortex

That portion of the brain responsible for mental functions, movements, visceral functions, perception, and behavioral reactions, and for the association and integration of these functions; the outer gray matter region of the cerebral hemispheres (Foss & Keteyian, 1998), (Marieb, 1998)

Cerebral Infarction

Death of brain tissue that results from insufficient blood supply attributable to blockage or damage of a cerebral vessel (also known as a stroke) (Wilmore & Costill, 2004)

Cerebral Thrombosis

            A blood clot in the brain (Foss & Keteyian, 1998)

Cerebral White Matter

Consists largely of myelinated fibers bundled into large tracts; provides for communication between cerebral areas and lower CNS centers (Marieb, 1998)

Cervical Vertebrae

            The seven vertebrae of the vertebral column located in the neck (Marieb, 1998)

Changing Component Abilities Hypothesis

The hypothesis that the set of abilities underlying a skill shifts systematically as practice continues (Schmidt & Lee, 1999)

Charles’s Law

The volume occupied by a gas (at constant pressure) is reduced or expanded in direct proportion to its temperature (Foss & Keteyian, 1998)

Chemical Bond

An energy relationship holding atoms together; involves the interaction of electrons (Marieb, 1998)

Chemical Energy

            Energy stored in the bonds of chemical substances (Marieb, 1998)

Chemical Reaction

            Process in which molecules are formed, changed, or broken down (Marieb, 1998)

Chemical Transmitter Substance

Stored in vesicles within the synaptic knobs of axons; released with the arrival of an impulse into the synaptic cleft or gap (Foss & Keteyian, 1998)


            Receptors sensitive to various chemicals in solution (Marieb, 1998)


The period of life between the first birthday and the onset of puberty (Wilmore & Costill, 2004)

Choice Reaction Time

Reaction time for a task in which each response to be made is associated with a different stimulus (Schmidt & Lee, 1999)


Steroid found in animal fats as well as in most body tissues; made by the liver (Marieb, 1998)

Cholinergic Fibers

            Nerve endings that, upon stimulation, release acetylcholine (Marieb, 1998)


A chemical that deactivates or breaks down acetylcholine (Foss & Keteyian, 1998)


            Actively mitotic cell form of cartilage (Marieb, 1998)


            Mature cell form of cartilage (Marieb, 1998)

Chronic Adaptation

A physiological change that occurs when the body is exposed to repeated exercise bouts over weeks or months; these changes generally improve the body’s efficiency at rest and during exercise (Wilmore & Costill, 2004)

Chronic Fatigue Syndrome

A syndrome that appears to involve immune system dysfunction; patients have incapacitating fatigue, sore throat, muscle tenderness or pain, and cognitive dysfunction; the symptoms may vary in severity over time but generally last for months or years (Wilmore & Costill, 2004)

Chronic Hypertrophy

An increase in muscle size that results from repeated long-term resistance training (Wilmore & Costill, 2004)

Chronic Obstructive Pulmonary Disease (COPD)

Collective term for progressive, obstructive respiratory disorders; includes emphysema, chronic bronchitis (Marieb, 1998)

Chronological Age

            Age measured in terms of months or years (Baechle & Earle, 2000)


            Rate of myocardial contractions (beats x min-1) (Foss & Keteyian, 1998)


            The combining of individual elements in memory into larger units (Schmidt & Lee, 1999)

Circa-Maximal Methods

A type of training in which all of the loads utilized are close to one’s 1RM (90% to 97%) (Siff, 2003)


            Movement of a body part so that it outlines a cone in space (Marieb, 1998)


Chronic disease of the liver, characterized by an overgrowth of connective tissue or fibrosis (Marieb, 1998)


The terminal ends of the longitudinal tubules of the sarcoplasmic reticulum which store Ca++; also called outer cisterns, outer vesicles, and terminal cisternae (Foss & Keteyian, 1998)

Classic Formula

A method of comparing lifts by dividing a lift by body weight to the two-thirds power thus accounting for the relationship of cross-sectional area versus volume (Baechle & Earle, 2000)

Closed-Loop System

A control system employing feedback, a reference of correctness, a computation of error, and subsequent correction in order to maintain a desired state; sometimes called a servomechanism or servo (Schmidt & Lee, 1999)

Closed Skills

            Skills that are performed in stable or predictable environmental settings (Schmidt & Lee, 1999)

Cluster Training

A form of interval training that requires one to perform one or more repetitions with a 10-20 second interval between each repetition or cluster of repetitions in an extended set (Siff, 2003)


            Process in which blood is transformed from a liquid to a gel; blood clotting (Marieb, 1998)


A so-called recreational drug that is a central nervous system stimulant which mimics the action of the sympathetic nervous system; it is generally ergolytic (Wilmore & Costill, 2004)

Coccygeal Vertebra

3 to 5 vertebrae which form a kind of vestigial internal tail extending downward from the pelvis (Baechle & Earle, 2000)

Cocktail Party Problem

The phenomenon, described by Cherry, whereby humans can attend to a single conversation at a noisy gathering, neglecting other inputs (Schmidt & Lee, 1999)


Agonist and antagonist muscles contracting simulataneously, with a dominance of the former producing external movement (Siff, 2003)


Nonprotein substance associated with and activating an enzyme, typically a vitamin (Marieb, 1998)

Cognitive Anxiety

            Psychological processes and worrisome thoughts (Baechle & Earle, 2000)

Cognitive Phase

The first of three phases of learning proposed by Fitts, in which learners’ performances are heavily based on cognitive or verbal processes (Schmidt & Lee, 1999)

Cognitive Plyometrics

A plyometric action produced under conditions in which the athlete anticipates a particular course of action (Siff, 2003)

Cognitive Psychology

A psychological tradition in which the nature of unobservable mental processes in human behavior is studied by indirect methods (Schmidt & Lee, 1999)

Collagen Fiber

The most abundant of the three fibers found in the matrix of connective tissue (Marieb, 1998)

Combination Training

Adding aerobic training to the training of anaerobic athletes with the goal of enhancing recovery; may reduce anaerobic performance capabilities as a result (particularly high-strength/high-power performance) (Baechle & Earle, 2000)

Commutative System

            A system in which the order of the operators does not matter: A*B = B*A (Siff, 2003)

Compensatory Acceleration Training

During a lift, proprioceptive feedback makes the athlete aware that the load is changing and enables him or her to intervene voluntarily in the loading process by accelerating or decelerating the bar to increase or decrease the force involved; can be useful in alternating muscle tension or movement velocity to achieve a specific training goal (Siff, 2003)

Complete Blood Count (CBC)

Clinical test that includes a hematocrit, counts all formed elements and clotting factors, and other indicators of normal blood function (Marieb, 1998)

Complementary Proteins

Proteins that do not contain all of the essential amino acids in and of themselves, but when combined with other incomplete proteins with the missing needed amino acids, can still provide all of the essential amino acids required by the body (Baechle & Earle, 2000)

Complex Training

Involves concurrent (during one workout) and parallel (prolonged stages of training) use of several training tasks and loads of different primary emphasis; one of the most effective forms of training construction (Siff, 2003)

Component Interaction

A characteristic of some tasks in which the adjustment on one component of the task requires an adjustment of some other component (Schmidt & Lee, 1999)


Substance composed of two or more different elements, the atoms of which are chemically united (Marieb, 1998)

Concentrated Loading

A training method associated with highly qualified athletes in which loads are concentrated during specific stages of preparation; a block of training is designed to emphasis one particular quality, such as strength, and all loads are prescribed to specifically address that quality (Siff, 2003)

Concentric Muscle Action

Muscle action in which the ends of the muscle are drawn closer (Foss & Keteyian, 1998)

Concurrent Feedback

            Feedback that is presented simultaneously with the action (Schmidt & Lee, 1999)

Concurrent System of Training

The parallel training of several motor abilities, such as strength, speed and endurance, over the same period, with the intention of producing multi-faceted development of physical fitness (Siff, 2003)


Augmentation of the energy capacity of muscle through a physical exercise program.  Conditioning is not primarily concerned with the skill of performance, as would be the case in training (Foss & Keteyian, 1998)

Conducting Zone

Includes all respiratory passageways that provide conduits for air to reach the sites of gas exchange (the respiratory zone) (Marieb, 1998)


The transfer of heat between objects of different temperatures in direct contact with each other (Foss & Keteyian, 1998)

Congenital Heart Disease

A heat defect present at birth that occurs from abnormal prenatal development of the heart or associated blood vessels; also known as congenital heart defect (Wilmore & Costill, 2004)

Congestive Heart Failure (CHF)

Condition in which the pumping efficiency of the heart is depressed so that circulation is inadequate to meet tissue needs (Marieb, 1998)

Conjugate Sequence System of Training

A training system involving the successive introduction of separate, specific means, each of which has a progressively stronger training effect, and coupling them sequentially to create favorable conditions for eliciting the cumulative effect of all the training loads (Siff, 2003)

Connective Tissues

A primary tissue; form and function vary extensively; functions include support, storage, and protection (Marieb, 1998)


The mechanism or process by which humans are aware of sensations, elements in memory, or internal events (Schmidt & Lee, 1999)

Conservation of Angular Momentum

The concept that angular momentum is constant unless the object is acted on by an external force (Hamill & Knutzen 2003)

Constant Error (CE)

With respect to sign, the average error of a set of scores form a target value (Schmidt & Lee, 1999)

Contextual Interference

The interference effects in performance and learning that arise from practicing one task in the context of other tasks (Schmidt & Lee, 1999)


Refers to a conditional consequence of the behavior that is being punished, such as being allowed to compete (Baechle & Earle, 2000)

Continuous Skills

            Skills that appear to have no recognizable beginning or end (Schmidt & Lee, 1999)

Continuous Tension Sets

Any set in which each repetition is done smoothly without ballistic bounce, cheating or significant pause at either end of the motion (Siff, 2003)

Continuous Work (Continuous Training)

Exercises performed to completion without relief periods (Foss & Keteyian, 1998)

Contractile Velocity

            The speed of action associated with specific muscle fiber types (Wilmore & Costill, 2004)


            Muscle cells’ ability to move by shortening (Marieb, 1998)


            To shorten or develop tension, an ability highly developed in muscle cells (Marieb, 1998)

Contraction Failure

            Inability of the muscle to shorten or lengthen under control (Baechle & Earle, 2000)


            Relating to the opposite side (Marieb, 1998)

Control Dynamics

The mechanical characteristics of the levers, handwheels, and the like in control systems; affected by variable such as spring tension and inertia that change the “feel” of control (Schmidt & Lee, 1999)

Controlled Processing

Information processing that is relatively slow, that is done serially with other processes, and that requires effort (compare with automatic processing) (Schmidt & Lee, 1999)


The transfer of heat from one place to another by the motion of a heated substance- e.g., air or water (Foss & Keteyian, 1998)

Converging Strength Training Means

A form of long-term organization of strength training; the convergence of all the different partial training effects to enhance specific performance (Siff, 2003)


Behavior of two or more degrees of freedom in relation to each other to produce skilled activity (Schmidt & Lee, 1999)

Core Temperature

Temperature of deep body tissues such as head, thorax, and digestive system (Foss & Keteyian, 1998)

Cori Cycle

A process where lactic acid from muscle metabolism diffuses into the blood and is carried to the liver for conversion to glucose where it can be used, stored, or released into the blood (Foss & Keteyian, 1998)

Coronary Artery Disease

Progressive narrowing of the coronary arteries (Wilmore & Costill, 2004)

Coronary Circulation

            The functional blood supply of the heart; shortest circulation in the body (Marieb, 1998)

Correlation Coefficient (r)

A statistical measure of the degree of linear association between two variables (Schmidt & Lee, 1999)

Cortical Bone

            Compact bone (Baechle & Earle, 2000)


            Steroid hormones released by the adrenal cortex (Marieb, 1998)

Cortisol (Hydrocortisone)

            Glucocorticoid produced by the adrenal cortex (Marieb, 1998)

Cost-Benefit Analysis

A method by which the benefits from anticipating correctly can be weighted against the “cost” of anticipating incorrectly (Schmidt & Lee, 1999)


A technique utilized to help an athlete confront fear; allows an athlete to replace a negative response to certain cues with a positive response (Baechle & Earle, 2000)

Coupled Reactions

Two series of chemical reactions, one of which releases energy (heat) for use by the other (Foss & Keteyian, 1998)

Coupling Time

The explosive isometric phase between the end of the eccentric action and the beginning of the concentric action during a plyometric movement (Siff, 2003)

Covalent Cross-Linking

Strong chemical bonds that form between adjacent collagen molecules throughout collagen bundles (Baechle & Earle, 2000)

Creatine Kinase

Enzyme that catalyzes the transfer of phosphate from phosphocreatine to ADP, forming creatine and ATP; important in muscle contraction (Marieb, 1998)

Creatine Phosphate (CP)

            Compound that serves as an alternative energy source for muscle tissue (Marieb, 1998)


A nitrogenous waste molecule which is not reabsorbed by the kidney; this characteristic makes it useful for measurement of the GFR and glomerular function (Marieb, 1998)


A series of inward membrane folds and convolutions within mitochondria that contain the enzyme systems required for aerobic metabolism (Foss & Keteyian, 1998)

Criterion Variable

In studies of prediction, the variable or score that is predicted from the predictor variables; the “best” obtaninable measure of the construct that is to be predicted (Schmidt & Lee, 1999)


            Extensions of myosin (Foss & Keteyian, 1998)


A surgical procedure in experimental animals where the nerve fibers to Type I and Type II muscle fibers are crossed over and reattached (Foss & Keteyian, 1998)


A receptor partially interacts with hormones that are not specifically designed for it (i.e., allosteric binding) (Baechle & Earle, 2000)


A cut running horizontally form right to left, dividing the body into superior and inferior parts (Marieb, 1998)

Cross-Training or Transfer of Training

A theory that developing one region or quality of the body will result in improvement of other region or quality; also used to describe potential benefits of combined running, biking, swimming, and/or weight training (Foss & Keteyian, 1998)

Crossed Extensor Reflex

A flexor reflex in one limb produces an extensor reflex in the contralateral limb approximately 0.2 to 0.5 seconds later (Siff, 2003)

Crossman-Goodeve Theory

A theory of the Fitts relationship that assumed a series of constant-duration movements, each interspersed with feedback-based corrections; an intermittent control theory of rapid movement (Schmidt & Lee, 1999)


            Pertaining to the production of low temperatures (Foss & Keteyian, 1998)

Cuff Technique

A method of temporary deafferentation in which blood flow to the limb is eliminated by a blood pressure cuff, rendering the afferent neurons anoxic so that they cannot deliver sensory information (Schmidt & Lee, 1999)

Current or Contemporary Control

Woodworth’s idea that the latter portions of a movement were controlled by a feedback-based “homing-in” process that allowed a target to be achieved (Schmidt & Lee, 1999)


            Pertaining to the skin (Marieb, 1998)

Cyclic Adenosine Monophosphate (Cyclic AMP)

Important intracellular second messenger that mediates hormonal effects; formed from ATP by the action of adenylate cyclase, an enzyme associated with the plasma membrane (Marieb, 1998)

Cyclic AMP Amplification

Impact of a hormone on a membrane causing cyclic AMP to form on the inside surface; has effect of multiplying the hormone effect (Foss & Keteyian, 1998)

Cyclic AMP Mechanism

The most common mechanism for the action of hormones on their target cells; hormones arrive at receptors and activate adenyl cyclase to speed cyclic AMP formation from ATP resulting in numerous specific actions (Foss & Keteyian, 1998)


Co-enzyme carriers containing iron (Fe++ and Fe +++ forms) that pass on hydrogen and associated electrons in the electron transport system (Foss & Keteyian, 1998)


Chemical mediators involved in cellular immunity; include lymphokines and monokines (Marieb, 1998)


Cell fluid that makes up the inside of cells; in muscle cells it is called sarcoplasm (Foss & Keteyian, 1998)


Dalton’s Law

The partial pressures of gases in a mixture remain constant and will act independently of each other (Foss and Keteyian, 1998)

Damping Efficiency

The ability of the body to absorb and dissipate shock or vibration; plays a major role in the storage and use of elastic energy, as well as the prevention of injury during activities involving rapid acceleration and deceleration (Siff, 2003)


Eliminating, usually by surgery (dorsal rhizotomy), the sensory input to the spinal cord while leaving efferent output intact (Schmidt & Lee, 1999)


            Removal of an amine group from an organic compound (Marieb, 1998)

Decomposition Reaction

Chemical reaction in which a molecule is broken down into smaller molecules or its constituent atoms (Marieb, 1998)

Decompression Sickness (Bends)

A condition in which bubbles of nitrogen are trapped in the blood and tissues during a too-rapid ascent from depth during diving; characterized by severe discomfort and pain (Wilmore & Costill, 2004)

Degrees of Freedom

The number of separate independent dimensions of movement in a system that must be controlled (Schmidt & Lee, 1999)

Degrees of Freedom Problem

The difficulty in explaining the simultaneous control of multiple, independently moving body parts (Schmidt & Lee, 1999)


            Condition of excessive water loss (Marieb, 1998)

Delayed Onset Muscular Soreness (DOMS)

Muscle soreness that develops a day or two after a heavy bout of exercise and that is associated with actual injury within the muscle (Wilmore & Costill, 2004)

Deliberate Practice

Identified by Ericsson as practice that is not inherently enjoyable and is undertaken for the sole purpose of improving performance (Schmidt & Lee, 1999)

DeLorme Method

Training in which a weight 50% of one’s 10RM is lifted 10 times for the first set, followed by a set of 10 repetitions at 75% of the 10RM, and finally a set of 10 reps at the 10RM weight (Siff, 2003)


            Short extensions from the body of a nerve cell (Foss and Keteyian, 1998)


            The measurement of body density (Wilmore & Costill, 2004)


            The mass per unit volume of an object (Foss and Keteyian, 1998)


            Loss of a state of polarity; loss or reduction of negative membrane potential (Marieb, 1998)

Depth Jumps

A type of plyometric training requiring an athlete to drop off of a raised surface (such as a box) onto another surface where upon the athlete jumps energetically; the optimal depth of the jump is determined by the athlete’s strength fitness and should ensure that significant dynamic force is developed without slowing down the transition from eccentric to concentric work by the muscles involved (Siff, 2003)

Depth Landings (Depth Drops)

A type of plyometric training requiring an athlete to drop off a raised surface (such as a box) and land on another surface without a rebounding jump; can have a significant effect on concentric and eccentric strength (Siff, 2003)


Changes in body structure or function caused by reduction or cessation of regular physical training (Foss and Keteyian, 1998)


Changes that occur in the body starting at conception and continuing through adulthood; differentiation along specialized lines of function, reflecting changes that accompany growth (Wilmore & Costill, 2004)

Diabetes Insipidus

Disease characterized by passage of a large quantity of dilute urine plus intense thirst and dehydration caused by inadequate release of antidiuretic hormone (ADH) (Marieb, 1998)

Diabetes Mellitus (DM)

Disease caused by deficient insulin release, leading to inability of the body cells to use carbohydrates (Marieb, 1998)


Any partition or wall separating one area from another; a muscle that separates the thoracic cavity from the lower abdominopelvic cavity (Marieb, 1998)

Diaphragmatic Breathing

Referred to as “belly breathing”, this form of breathing is a basic stress management technique and a precursor to all other mental training techniques; it focuses thought on breathing to clear the mind and therefore increase attentional capacity (Baechle & Earle, 2000)


            Elongated shaft of a long bone (Marieb, 1998)


            Freely movable joint (Marieb, 1998)


Period of the cardiac cycle when either the ventricles or the atria are relaxing (Marieb, 1998)

Diastolic Pressure

Arterial blood pressure reached during or as a result of diastole; lowest level of any given ventricular cycle (Marieb, 1998)

Diastolic Volume

            The amount of blood that fills the ventricle during diastole (Foss and Keteyian, 1998)

Dietary Reference Intakes (DRIs)

Recommendations of the Food and Nutrition Board of the National Academy of Sciences for the intake of vitamins and minerals to be used for planning and assessing diets for healthy people (Baechle & Earle, 2000)

Differential Approach

That approach to the study of behavior that focuses on individual differences, abilities, and prediction (Schmidt & Lee, 1999)


Depending on the particular paradigm, either the ratio of the amplitude to the target widths or the ratio of the movement amplitude to movement time (Schmidt & Lee, 1999)


The spreading of particles in a gas or solution with a movement toward uniform distribution of particles (Marieb, 1998)


Chemical or mechanical process of breaking down foodstuffs into substances that can be absorbed (Marieb, 1998)

Diminishing Sets

A method of training in which an athlete tries to perform a very large number of repetitions (usually 100) in as few sets as possible with the same load, with a minimal rest period between sets; when one is capable of executing the 100 repetitions in 4 to 5 sets, the load should be increased for the next workout (Siff, 2003)


            A combination of two amino acids united by means of a peptide bond (Marieb, 1998)


            The internal layer of spongy bone in flat bones (Marieb, 1998)

Direct Calorimetry

A method that gauges the body’s rate and quantity of energy production by direct measurement of the body’s heat production (Wilmore & Costill, 2004)

Direct Gene Activation

The method of action of steroid hormones; they bind to receptors in the cell, and then the hormone-receptor complex enters the nucleus and activates certain genes (Wilmore & Costill, 2004)


            Literally, double sugar; sucrose, lactose (Marieb, 1998)

Discrete Skills

            Skills that have a definite beginning and end (Schmidt & Lee, 1999)

Discrimination Reaction Time

Reaction time for a task in which a number of stimuli can be presented, with a response being made only if a given stimulus occurs (Schmidt & Lee, 1999)

Dislocation (Luxation)

            Occurs when bones are foced out of their normal alignment at a joint (Marieb, 1998)

Disordered Eating

Abnormal eating behavior that ranges from excessive restriction of food intake to pathological behaviors, such as self-induced vomiting and laxative abuse; disordered eating can lead to clinical eating disorders, such as anorexia nervosa and bulimia nervosa (Wilmore & Costill, 2004)

Displacement Reaction

Chemical reaction in which bonds are both made and broken; atoms become combined with different atoms (Marieb, 1998)


A strategy in which an athlete will distract him or herself from their performance and perceived physiological state while engaged in activity to try and reduce pain and fatigue (Baechle & Earle, 2000)


            Away from the attached end of a limb or the origin of a structure (Marieb, 1998)


Negative stress; detrimental stress that causes decay, damage, death, or disease (Baechle & Earle, 2000) (Siff, 2003)

Distributed Loading

Training in which a gradual increase in functional indicators is associated with a moderate volume of continuous loading (Siff, 2003)

Distributed Practice

A sequence of practice and rest periods in which the practice time is relatively restful, often equal to or less than the rest time (Schmidt & Lee, 1999)


            Chemicals that enhance urinary output (Marieb, 1998)

Diurnal Variation

            Normal fluctuations in hormone levels throughout the day (Baechle & Earle, 2000)

DNA (Deoxyribonucleic Acid)

A nucleic acid found in all living cells; it carries the organism’s hereditary information (Marieb, 1998)


            An excitatory neurotransmitter chemical (Foss and Keteyian, 1998)


            Pertaining to the back; posterior (Marieb, 1998)

Dorsal Rhizotomy

The cutting of the dorsal roots at various segmental levels of the spinal cord, resulting in deafferentation from the associated areas of the body (Schmidt & Lee, 1999)

Dorsal Root

The collection of nerve fibers from the periphery into a bundle near the posterior side of the spinal cord at each spinal level; the major sensory input to the cord (Schmidt & Lee, 1999)

Double-Blind Study

An experimental protocol in which neither the investigators nor the subjects know which group is receiving a placebo and which group is receiving the real drug or treatment (Foss and Keteyian, 1998)

Douglas Bag

A rubber-lined, canvas bad used for collection of expired gas; rubber meterologic balloons now are used (Foss and Keteyian, 1998)


Decreased response to hormonal stimulation; involves a loss in the number of receptors and effectively prevents the target cells from overreacting to persistently high hormone levels (Marieb, 1998)


A chemical substance given with the intention of preventing or curing disease or otherwise enhancing the physical or mental welfare of humans or animals (Foss and Keteyian, 1998)

Dry Bulb Thermometer

            A common thermometer used to record temperature of the air (Foss and Keteyian, 1998)

Dual-Energy X-Ray Absorptiometry (DEXA)

A technique used to assess both regional and total body composition through the use of X-ray absorptiometry (Wilmore & Costill, 2004)

Dynamic Action

            Any muscle action that produces joint movement (Wilmore & Costill, 2004)

Dynamic Analysis

A calculation of the forces and moments when there are significant linear and/or angular accelerations (Hamill & Knutzen 2003)



Dynamic Correspondence

A principle of training that emphasizes that the means and methods of strength training for specific sports should be chosen to enhance the required motor qualities in terms of the amplitude and direction of movement, the accentuated region of force production, the dynamics of the effort, the rate and time of maximum force production, and the regime of muscular work (Siff, 2003)

Dynamic Equilibrium

            Sense that reports on angular or rotary movements of the head in space (Marieb, 1998)

Dynamic Flexibility

The opposition or resistance of a joint to motion; forces opposing movement rather than the range of movement itself, which is static flexibility (Foss and Keteyian, 1998)

Dynamic Pattern Theory

A view that describes coordination as a self-organizing process of pattern formation (Schmidt & Lee, 1999)

Dynamic Stabilization

Muscles contract continuously to stabilize a body segment during a movement while simultaneously carrying out a mobilizing role (Siff, 2003)

Dynamic Stretching

Umbrella term for non-static stretches including ballistic stretching, active stretching, PNF stretching, and plyometric stretching (Siff, 2003)


The branch of mechanics in which the system being studied undergoes acceleration (Hamill & Knutzen 2003)

Dynamometric Profile

Characterizes the strength topography of representative muscle groups of athletes of different specialization, as well as the changes in the general profile with growth of sports mastery; reflects the characteristics of the strength fitness of athletes in a given sport and can serve to some extent as a standard for controlling the training process (Siff, 2003)


            Disorders of muscle tone, posture, or involuntary movements (Marieb, 1998)


            Painful menstruation (Foss and Keteyian, 1998)


            Labored breathing (Foss and Keteyian, 1998)


Eating Disorders

Psychological problems that manifest in disturbed eating patterns; malnutrition is secondary to the disease; the root of eating disorders is complex and multifactorial, with the etiology of the problem linked to self-esteem, family dynamics, stress, sense of loss of control, sexual abuse, and other sources (Baechle & Earle, 2000)

Early Responding

Processing all of the aspects of a movement in advance so that the movement can occur at or before the stimulus (Schmidt & Lee, 1999)

Eccentric Force

            A force that is not applied through the center of mass of an object (Hamill & Knutzen 2003)

Eccentric Muscle Action

Muscle action in which a force external to the muscle overcomes the muscle force and the ends of the muscle are drawn further apart (Foss and Keteyian, 1998)

Eccrine Glands

            Sweat glands abundant on the palms, soles of feet, and the forehead (Marieb, 1998)

Ecological Viewpoint

A point of view emphasizing the study of movement in natural environments (Schmidt & Lee, 1999)


Embryonic germ layer; forms the epidermis of the skin and its derivatives, and nervous tissues (Marieb, 1998)


A body type component characterized by linearity, fragility, and delicacy of body (Foss and Keteyian, 1998)


            Abnormal accumulation of fluid in body parts or tissues; causes swelling (Marieb, 1998)

Effective Target Width (We)

The size of the target area that the performer actually uses in a series of aiming movements, calculated as the standard deviation of the movement endpoints (Schmidt & Lee, 1999)


            Organ, gland, or muscle capable of being activated by nerve endings (Marieb, 1998)

Effector Anticipation

Predicting the duration of internal processes for a planned movement so that it can be made coincident with some anticipated external event (Schmidt & Lee, 1999)


Carrying away or away from, especially a nerve fiber that carries impulses away from the central nervous system (Marieb, 1998)


The ratio of work output to work input expressed as a percentage (Foss and Keteyian, 1998)

Effort Arm

            See Moment Arm (Hamill & Knutzen 2003)

Effort Force

            A force applied to a lever, causing movement of the lever (Hamill & Knutzen 2003)

Ejection Fraction

            The fraction of the end-diastolic volume ejected from the heart (Baechle & Earle, 2000)

Elaboration and Distinctiveness Hypothesis

A view of contextual interference that emphasizes the comparative and contrastive value of tasks in short-term memory (Schmidt & Lee, 1999)

Elastic Cartilage

            Cartilage with abundant elastic fibers; more flexible than hyaline cartilage (Marieb, 1998)

Elastic Fiber

Fiber formed from the protein elastin, which gives a rubbery and resilient quality to the matrix of connective tissue (Marieb, 1998)


            An extensible protein (Baechle & Earle, 2000)

Electrical Potential

The capacity for producing electrical effects, such as an electric current, between two bodies (e.g., between the inside and outside of a cell) (Foss and Keteyian, 1998)

Electrical Stimulation Training

            Stimulation of a muscle by passing an electrical current through it (Wilmore & Costill, 2004)

Electrocardiogram (ECG or EKG)

            Graphic record of the electrical activity of the heart (Marieb, 1998)

Electrochemical Gradient

The distribution of ions involving both a chemical and an electrical gradient interacting to determine the direction of diffusion (Marieb, 1998)

Electromechanical Delay Phase

Occurs when some event such as contact with a surface prevents a limb from moving further and provokes the muscles to contract; the delay refers to the time elapsing between the onset of the action potential in the motor nerves and the onset of the muscle contraction (Siff, 2003)

Electromyography (EMG)

            A recording of the electrical activity from muscles (Schmidt & Lee, 1999)


Chemical substances, such as salts, acids, and bases, that ionize and dissociate in water and are capable of conducting an electrical current (Marieb, 1998)

Electrolyte Balance

Refers to the balance between input and output of salts (sodium, potassium, calcium, magnesium) in the body (Marieb, 1998)


            A negatively charged particle (Foss and Keteyian, 1998)

Electron Micrographs

Photographs of tissues as magnified thousands of times in an electron microscope (Foss and Keteyian, 1998)

Electron Transport Chain (ETC)

A series of chemical reactions that convert the hydrogen ion generated by glycolysis and the Krebs cycle into water and produce energy for oxidative phosphorylation (Wilmore & Costill, 2004)


Obstruction of a blood vessel by an embolus (blood clot, fatty mass, bubble of air, or other debris) floating in the blood (Marieb, 1998)

Emergency Muscles

A special class of assistant movers which come into play only when maximal force must be generated during a particular movement (Siff, 2003)

Emergency Stabilizers

Muscles which are recruited in addition to the primary stabilizers to help stabilize a body segment during very intensive efforts by the prime and assistant movers (Siff, 2003)

Empirical Equation

An equation describing the outcome of an experiment in which the functional mathematical relationship is estimated from the empirical observations (Schmidt & Lee, 1999)

End Branches

Branches coming off the ends of the axons leading to the axon terminals (Wilmore & Costill, 2004)

End-Diastolic Volume

The volume of blood available to be pumped by the ventricle at the end of the filling phase, or diastole (Baechle & Earle, 2000)

End-Systolic Volume

The volume of blood remaining in the left ventricle at the end of systole, just after contraction (Wilmore & Costill, 2004)

Endergonic Reaction

Chemical reaction that absorbs energy, otherwise known as an anabolic reaction (Marieb, 1998)


            Endothelia membrane that lines the interior of the heart (Marieb, 1998)

Endochondral Ossification

Embryonic formation of bone by the replacement of calcified cartilage; most skeletal bones formed by the process (Marieb, 1998)

Endocrine Glands

            Ductless glands that empty their hormonal products directly into the blood (Marieb, 1998)

Endocrine System

            Body system that includes internal organs that secrete hormones (Marieb, 1998)


            Thin connective tissue surrounding each muscle cell (Marieb, 1998)


A body type component characterized by roundness and softness of the body (Foss and Keteyian, 1998)


One of several substances in the general category of endogenous opioid peptides that may provide mood altering, pain-reduction, and relaxing benefits; implicated in phenomena known as “runner’s high” and “exercise addiction” (Foss and Keteyian, 1998)


            Connective tissue membrane covering internal bone surfaces (Marieb, 1998)


Single layer of simple squamous cells that line the walls of the heart, blood vessels, and lymphatic vessels (Marieb, 1998)


The time limit of a person’s ability to maintain either an isometric force or a power level involving combinations of concentric and/or eccentric muscle actions (Foss and Keteyian, 1998)


The capacity to do work, may be stored (potential energy) or in action (kinetic energy) (Marieb, 1998)

Energy Capacity

The maximal amount of energy that can be liberated by a metabolic system; independent of time but using all available stores of fuel substrate (Foss and Keteyian, 1998)

Energy Continuum

A conceptual model whereby the energy required for mostly anaerobic, mixed, and mostly aerobic activities is provided via a greater or lesser use of the same metabolic pathways (Foss and Keteyian, 1998)

Energy Density

            Refers to the calories per weight or volume of food (Baechle & Earle, 2000)

Energy Intake

            Energy liberated during food oxidation (Marieb, 1998)

Energy Nutrients

Sources of usable energy from food; carbohydrates, fats, and proteins (Foss and Keteyian, 1998)

Energy Output

            Sum of energy lost as heat, as work, and as fat or glycogen storage (Marieb, 1998)

Energy State Regulation

A mechanism of control over cellular metabolism that is tightly linked to the ongoing use of energy and the rate of ADP production (Foss and Keteyian, 1998)

Energy Substrate

Molecules that provide starting materials for bioenergeic reactions; include phosphagens (ATP and creatine phosphate), glucose, glycogen, lactate, free fatty acids, and amino acids (Baechle & Earle, 2000)

Energy System

One of three metabolic systems involving a series of chemical reactions resulting in the formation of waste products and the manufacture of ATP (Foss and Keteyian, 1998)


A memorized motor pattern stored in the brain; a permanent trace left by a stimulus in the tissue protoplasm (Foss and Keteyian, 1998)


The combination of the various sources of sensory information that enable accurate perception of movement and position (Schmidt & Lee, 1999)


            A protein that acts as a biological catalyst to speed up a chemical reaction (Marieb, 1998)

Ependymal Cell

A type of CNS supporting cell; lines the central cavities of the brain and spinal cord (Marieb, 1998)

Epidural Space

            Area between the bony vertebrae and the dura mater of the spinal cord (Marieb, 1998)


            Sheath of fibrous connective tissue surrounding a muscle (Marieb, 1998)


Chief hormone produced by the adrenal medulla; also called adrenaline; a hormone secreted by the medulla of the adrenal gland that has effects on the heart, the blood vessels, metabolism, and the CNS (Marieb, 1998), (Foss and Keteyian, 1998)

Epiphyseal Plate

Plate of hyaline cartilage at the junction of the diaphysis and epiphysis that provides for growth in length of a long bone (Marieb, 1998)


            The end of a long bone, attached to the shaft (Marieb, 1998)


Pertaining to a primary tissue that covers the body surface, lines its internal cavities, and forms glands (Marieb, 1998)


            The state of a system whose acceleration is unchanged (Hamill & Knutzen 2003)

Equilibrium Point

For a given level of muscle activation, the hypothetical joint angle at which the torques from the two opposing muscle groups are equal and opposite (Schmidt & Lee, 1999)

Equilibrium Point Models (a and l)

Limb control models in which a movement endpoint is produced through the specification of an equilibrium point between the agonist and the antagonist muscle groups (Schmidt & Lee, 1999)


            Able to improve work or performance (Wilmore & Costill, 2004)

Ergogenic Aid

            Any factor that improves work performance (Foss and Keteyian, 1998)


            Able to impair work or performance (Wilmore & Costill, 2004)


An apparatus or device, such as a treadmill or stationary cycle, used for measuring the physiological effects of exercise (Foss and Keteyian, 1998)


            The study of human beings in work environments (Schmidt & Lee, 1999)

Error in Execution

An error in which the planned spatial-temporal goal of a movement is appropriate, but the movement deviates from the desired path because of factors occurring during execution (Schmidt & Lee, 1999)

Error in Selection

An error in which the planned spatial-temporal goal is inappropriate given the nature of the environment (Schmidt & Lee, 1999)


            Red blood cells (Marieb, 1998)


            Process of erythrocyte formation (Marieb, 1998)


            Hormone that stimulates production of red blood cells (Marieb, 1998)

Essential Amino Acids

The eight or nine amino acids necessary for human growth that the body cannot synthesize and are thus essential parts of our diets (Wilmore & Costill, 2004)

Essential Hypertension

Abnormally high blood pressure in humans that has no known cause and therefore no known cure; most common type of high blood pressure (Foss and Keteyian, 1998)

Essential Nutrients

Nutrients that cannot be manufactured by the body or are manufactured at a pace that is slower than the body’s needs (e.g., linoleic acid) (Foss and Keteyian, 1998)


A hormone of the estrogen category; the primary form produced by the human ovaries; produces female secondary sex characteristics and causes estrus in animals (Foss and Keteyian, 1998)


Hormones that stimulate female secondary sex characteristics; female sex hormones (Marieb, 1998)


            Normal menstrual function (Wilmore & Costill, 2004)


            Positive stress; beneficial stress which produces growth (Baechle & Earle, 2000) (Siff, 2003)


            The loss of heat resulting from changing a liquid to a vapor (Foss and Keteyian, 1998)

Excess Postexercise Oxygen Consumption (EPOC)

The oxygen uptake above resting values used to restore the body to the preexercise condition (Baechle & Earle, 2000)


            A response to a stimulus (Foss and Keteyian, 1998)

Excitation-Contraction Coupling

Sequence of events by which transmission of an action potential along the sarcolemma leads to the sliding of myofilaments (Marieb, 1998)

Excitatory Postsynaptic Potential (EPSP)

A transient increase in electrical potential (depolarization) from its resting membrane potential in a postsynaptic neuron (Foss and Keteyian, 1998)


Any and all activity involving the generation of force by the activated muscles; exercise can be quantified mechanically as force, torque, work, power, or velocity of progression (Foss and Keteyian, 1998)

Exercise Electrocardiogram

            A recording of the heart’s electrical activity during exercise (Wilmore & Costill, 2004)

Exercise-Induced Arterial Hypoxemia

A decline in arterial partial pressure of oxygen and arterial oxygen saturation during maximal or near-maximal exercise (Wilmore & Costill, 2004)

Exercise Intensity

A specific level of muscular activity that can be quantified in term s of power (energy expenditure or work performed per unit of time), the opposing force (e.g., free weights), isometric force sustained, or velocity of progression (Foss and Keteyian, 1998)

Exercise Physiology

Scientific study of how the body, from a functional standpoint, responds, adjusts, and adapts to acute exercise and chronic training (Foss and Keteyian, 1998)

Exercise Prescription

Individualization of the prescription of exercise duration, frequency, intensity, and mode (Wilmore & Costill, 2004)

Exercise Pressor Reflex

An afferent feedback mechanism to the cardiorespiratory areas of the medulla that originates in the skeletal muscles, mainly via mechanoreceptors and metaboreceptors (Foss and Keteyian, 1998)


            The performance of light exercise during recovery from exercise (Foss and Keteyian, 1998)

Exergonic Reaction

            Chemical reaction that releases energy, a catabolic or oxidative reaction (Marieb, 1998)


            Inability to continue exercise (Wilmore & Costill, 2004)


Amino acid-specifying informational sequences (separated by introns) in the genes of higher organisms (Marieb, 1998)

Expectancy Theory of Motivation

A theory which states that it is not merely a specific goal, but rather the individual perception of that goal which motivates people; motivation depends upon the perceived attractiveness of the goal and the perceived probability of achieving that goal (Siff, 2003)

Expected Sensory Consequences

A construct in schema theory; the anticipated feedback sensations that should be received if the movement is correct (Schmidt & Lee, 1999)


The process by which air is force out of the lungs through relaxation of the inspiratory muscles and elastic recoil of the lung tissue, which increases the pressure in the thorax (Wilmore & Costill, 2004)

Expiratory Reserve Volume (ERV)

            Maximal volume of air expired from end-expiration (Foss and Keteyian, 1998)

Explosive Ballistic Muscle Tension

Tension characteristic of movements in which maximal force is applied against a relatively small resistance (such as a shot put); the motive force reaches a maximum quickly in the beginning and middle ranges of the movement, then begins to diminish (Siff, 2003)

Explosive Isometric Muscle Tension

Inherent to movements in which significant resistance is overcome such as when snatching or cleaning a barbell; a basic characteristic of these movements is the need to develop a large working force whose maximum is achieved isometrically at the end of the movement (Siff, 2003)

Explosive Reactive Ballistic Muscle Tension

Has similar characteristics to that of explosive ballistic muscle tension except for the regime of muscular work; the preliminary stretch phase is sharp and pronounced, after which there is an immediate change to concentric work (Siff, 2003)

Explosive Strength

            The ability to produce maximal force in a minimal amount of time (Siff, 2003)


            Movement that increases the angle of a joint, straightening a flexed knee (Marieb, 1998)

Extensive Methods

            Training methods involving large training volume (Siff, 2003)

External Respiration

The process of brining air into the lungs and the resulting exchange of gas between the alveoli and the capillary blood (Wilmore & Costill, 2004)

External Work

            The work done by a body on another body (Hamill & Knutzen 2003)


            Sensory end organ that responds to stimuli from the external world (Marieb, 1998)


            Outside the cell (Foss and Keteyian, 1998)

Extracellular Fluid

The 35% to 40% of the water in the body that is outside the cells, including interstitial fluid, blood plasma, lymph, cerebrospinal fluid, and other fluids (Wilmore & Costill, 2004)

Extrafusal Fiber

            A typical or normal muscle cell or fiber (Foss and Keteyian, 1998)


            Premature heart contraction (Marieb, 1998)

Extrinsic Neural Control

Redistribution of blood at the system or body level through neural mechanisms (Wilmore & Costill, 2004)


Facilitated Diffusion

            Diffusion that takes place with the help of a carrier substance (Foss and Keteyian, 1998)

Factor Analysis

A complex statistical procedure wherein a large number of separate tests are grouped into a smaller number of factors, each of which is thought to represent an underlying ability (Schmidt & Lee, 1999)

Factor Loading

In factor analysis, the statistical values indicating the extent to which the tests measure the various factors (Schmidt & Lee, 1999)

Fartlek Training (Speed Play)

An informal interval-training-type method for endurance performance that involves alternating a fast and a slow training pace over natural terrain; neither the work nor relief intervals are precisely timed; it is the forerunner of the interval training system (Foss and Keteyian, 1998)


            Layers of fibrous tissue covering and separating muscle (Marieb, 1998)


            Bundle of nerve or muscle fibers bound together by connective tissues (Marieb, 1998)

Fast Component (of recovery)

The initial, rapid decline in oxygen consumption at the start of recovery from exercise, usually lasting 3 to 4 minutes (reported in liters); formerly alactacid oxygen debt (Foss and Keteyian, 1998)

Fast Glycolysis

Chemical reaction in which pyruvate is converted to lactic acid, providing energy (ATP) at a fast rate compared with slow glycolysis (Baechle & Earle, 2000)

Fast-Twitch (FT) Fiber

A muscle fiber characterized by fast contraction time, high anaerobic capacity, and low aerobic capacity, all making the fiber suited for high-power output activities; also known as Type II fiber (Foss and Keteyian, 1998)


A compound containing glycerol and fatty acids (Foss and Keteyian, 1998)



Fat-Free Mass

The mass (weight) of the body that is not fat, including muscle, bone, skin, and organs (Wilmore & Costill, 2004)

Fat-Soluble Vitamins

A category of vitamins that are fat soluble and consequently are stored in the body in the liver and fatty tissues; need not be supplied each day but excessive accumulations can cause toxic effects; vitamins A, D, E, and K (Foss and Keteyian, 1998)


A state of discomfort and decreased efficiency resulting from prolonged or excessive exertion (Foss and Keteyian, 1998)

Fatty Acids

Linear chains of carbon and hydrogen atoms (hydrocarbon chains) with an organic acid group at one end; a constituent of fat (Marieb, 1998)


            Sensory information that results from movement (Schmidt & Lee, 1999)

Feedfoward Control

The sending of information ahead in time to ready a part of the system for incoming sensory feedback or for a future motor command (Schmidt & Lee, 1999)


            A slender, threadlike structure or filament (Marieb, 1998)

Fiber-Nerve Ratio (F:N)

The number of muscle fibers in a motor unit in relationship to the motor neuron axon that is innervating it (Foss and Keteyian, 1998)


            Condition of rapid and irregular or out-of-phase heart contractions (Marieb, 1998)


            Fibrous, insoluble protein formed during blood clotting (Marieb, 1998)


            The dissolving of a blood clot (Foss and Keteyian, 1998)


            Young, actively mitotic cell that forms the fibers of connective tissue (Marieb, 1998)


The most compressible type of cartilage; resistant to stretch; forms vertebral discs and knee joint cartilages (Marieb, 1998)


            Mature fibroblast; maintains the matrix of fibrous types of connective tissue (Marieb, 1998)

Fibromyalgia Syndrome

A chronic syndrome that includes muscle pain as its dominant symptom but is also characterized by muscle weakness, migraine-type headaches, and depression (Wilmore & Costill, 2004)


            Proliferation of fibrous connective tissue called scar tissue (Marieb, 1998)

Fibrous Attachment

A type of muscle attachment that involves a tendon which blends into and are continuous with both the muscle sheaths and the connective tissue surrounding the bone (Baechle & Earle, 2000)

Fibrous Joints

            Bones joined by fibrous tissue; no joint cavity is present (Marieb, 1998)

Fick Equation

Expresses the relationship of cardiac output, oxygen uptake, and arteriovenous oxygen difference (Baechle & Earle, 2000)

First-Class Lever

A lever for which the muscle force and resistive force act on opposite sides of the fulcrum; a lever in which the fulcrum is between the effort force and the resistance force (Baechle & Earle, 2000) (Hamill & Knutzen 2003)


            The ability of the body to cope with a specific task under specific conditions (Siff, 2003)

Fitt’s Law

Mathematical description of the speed-accuracy trade-off in which the average movement time is linearly related to Log2(2A/W) (Schmidt & Lee, 1999)


Muscle that immobilizes one or more bones; allowing other muscles to act from a stable base (Marieb, 1998)


            Lacking muscular tonus (Foss and Keteyian, 1998)

Flavin Adenine Dinucleotide

An acceptor and carrier of hydrogen from the Krebs cycle to the electron transport system (Foss and Keteyian, 1998)

Fleshy Attachment

Muscle fibers are directly affixed to the bone; usually over a wide area so that force is distributed rather than localized (Baechle & Earle, 2000)


Refers to the range of movement of a specific joint with respect to a particular degree of freedom; each joint exhibits statically or dynamically some or many degrees of freedom (Siff, 2003)


Movement that decreases the angle of the joint, e.g., bending the knee from a straight to an angled position (Marieb, 1998)

Flexor Reflex

Reflex initiated by a painful stimulus (actual or perceived); causes automatic withdrawal of the threatened body part from the stimulus (Marieb, 1998)

Floor Effect

A limitation, imposed either by the scoring system or by physiological-psychological limits, that places a minimum on the score that a performer can achieve in a task (Schmidt & Lee, 1999)

Fluid Resistance

The resistive force encountered by an object moving through a fluid (liquid or gas) or by a fluid moving past or around an object or through an orifice; encountered by swimmers, sprinters, throwers, etc (Baechle & Earle, 2000)

Follicle-Stimulating Hormone (FSH)

Hormone produced by the anterior pituitary that stimulates ovarian follicle production in females and sperm production in males (Marieb, 1998)

Food Guide Pyramid

A tool designed to provide guidance for evaluating nutrient adequacy of the diet; developed by the U.S. Department of Agriculture (Baechle & Earle, 2000)

Foot-Pound (ft-lb)

A work unit; that is, application of a one-pound force through a distance of one foot (Foss and Keteyian, 1998)


            Hole or opening in a bone or between body cavities (Marieb, 1998)


That which changes or tends to change the state of rest or motion in matter (SI unit: Newton); a muscle generates force in a muscle action (Foss and Keteyian, 1998)

Force Couple

Two forces that are equal in magnitude, act in opposite directions at a distance from an axis of rotation, and produces rotation with no translation (Hamill & Knutzen 2003)

Force Variability

The within-subject variability in a series of forces produced either in static or in dynamic contractions (Schmidt & Lee, 1999)


            The interval between a warning signal and the stimulus to respond (Schmidt & Lee, 1999)


The loss of memory, or the loss of the acquired capability for responding (Schmidt & Lee, 1999)

Forgetting and Reconstruction Hypothesis

A view of contextual interference that emphasizes the role of the construction of previously forgotten action plans as a basis of learning (Schmidt & Lee, 1999)

Form Drag

Resistance that results from the way in which a fluid presses against the front or rear of an object passing through it (Baechle & Earle, 2000)

Formed Elements

            Cellular portion of blood (Marieb, 1998)


            A depression, often an articular surface (Marieb, 1998)


            A pit (Marieb, 1998)


            A break in a bone (Marieb, 1998)

Frank-Starling Mechanism

A change in cardiac performance (i.e., stroke work) as a function of preload or stretch of the cardiac muscle prior to contraction (Foss and Keteyian, 1998)

Free Fatty Acids

            The components of fat that are used by the body for metabolism (Wilmore & Costill, 2004)

Free Radicals

Highly reactive chemicals with unpaired electrons that can scramble the structure of proteins, lipids, and nucleic acids (Marieb, 1998)

Free Weight

An object of known mass, not attached to a supporting or guiding structure, which is used for physical conditioning and competitive lifting (Foss and Keteyian, 1998)

Frequency of Activation

A method of varying muscular force output; increasing the frequency of activation of motor units intensifies force output (Baechle & Earle, 2000)


The resistive force encountered when one attempts to move two objects in contact with each other (Baechle & Earle, 2000)

Frontal (Coronal) Plane

Longitudinal (vertical) plane that divides the body into anterior and posterior parts (Marieb, 1998)


            The fixed point on which a lever moves when a force is applied (Marieb, 1998)

Functional Residual Capacity (FRC)

            Volume of air in the lungs at resting expiratory level (Foss and Keteyian, 1998)

Functional Resistance Machines

Training machines designed to provide resistance to various movements encountered in sport; simple pulley machines (Siff, 2003)

Functional Strength Training

Strength training involving intermuscular coordination between different muscle groups, intramuscular coordination of fibers within the same muscle group (number encoding, rate encoding, pattern encoding), facilitator and inhibitory reflexive processes, and motor learning (Siff, 2003)

Fusimotor Neurons

            The nerve cells of the CNS whose thin axons innervate the intrafusal fibers of the muscle s          pindles; also called gamma motor neurons (Foss and Keteyian, 1998)



The relationship between the amount of input to a system and the output produced by it; usually expressed as a ratio (Schmidt & Lee, 1999)

Gamma-Aminobutryic Acid (GABA)

            An inhibitory neurotransmitter substance (Foss and Keteyian, 1998)

Gamma Motor Neuron

A type of efferent nerve cell that innervates the ends of an intrafusal muscle fiber (Foss and Keteyian, 1998)

Gamma System (Gamma Loop)

The contraction of a muscle as a result of stretch the muscle spindle by way of stimulation of the gamma motor neurons (Foss and Keteyian, 1998)


            Collection of nerve cell bodies outside the CNS (Marieb, 1998)

Gastric Emptying

The movement of food mixed with gastric secretions from the stomach into the duodenum (Wilmore & Costill, 2004)

Gearshift Analogy

An idea presented by Keele about the learning of motor programs, analogous to learning to shift gears in an automobile (Schmidt & Lee, 1999)


One of the biological units of heredity located in chromatin; transmits hereditary information (Marieb, 1998)

General Adaptation Syndrome

Hans Seyle’s theory that all animals exposed to periods of stress undergo three phases: initial alarm, resistance, and exhaustion (Siff, 2003)

General Motor Ability

An early concept in which a single ability was thought to account for major portions of the individual differences in motor behavior (Schmidt & Lee, 1999)

General Physical Preparation (GPP)

Training intended to provide balanced physical conditioning in endurance, strength, speed, flexibility, and other basic factors of fitness (Siff, 2003)

Generalized Motor Program

A motor program whose expression can be varied depending on the choice of certain parameters (Schmidt & Lee, 1999)

Genetic Code

Refers to the rules by which the base sequence of a DNA gene is translated into protein structures (amino acid sequences) (Marieb, 1998)


The complete set of chromosomes derived from one parent (the haploid genome); or, the two sets of chromosomes, i.e., one set from the egg, the other from the sperm (the diploid genome) (Marieb, 1998)


            One’s genetic makeup or genes (Marieb, 1998)


Organ specialized to secrete or excrete substances for further use in the body or for elimination (Marieb, 1998)


            Opening between the vocal cords in the larynx (Marieb, 1998)


Hormone formed by alpha cells of islets of Langerhans in the pancreas; raises the glucose level of blood (Marieb, 1998)


Adrenal cortex hormones that increase blood glucose levels and aid the body in resisting long-term stressors (Marieb, 1998)


            Formation of glucose from noncarbohydrate molecules (Marieb, 1998)


            Principal blood sugar; a hexose (Marieb, 1998)

Glucose-Alanine Cycle

Glucose made in the liver from pyruvic acid that is carried there in the form of alanine; the alanine being originally formed in muscle by combining –NH2 radicals from metabolized amino acids with pyruvate (Foss and Keteyian, 1998)

Glycemic Index (GI)

Classifies a food by how high and how long it raises blood glucose (i.e., the food’s glycemic response) (Baechle & Earle, 2000)


            A modified simple sugar (a sugar alcohol) (Marieb, 1998)


A simple amino acid, thought to be the main inhibitory transmitter in the spinal cord (Foss and Keteyian, 1998)


Large carbohydrate molecules that compose ground substance in cartilage (Baechle & Earle, 2000)


            Main carbohydrate stored in animal cells; a polysaccharide (Marieb, 1998)

Glycogen-Loading (Supercompensation)

A diet or exercise-diet procedure that elevates muscle glycogen stores to concentrations two to three times normal (Foss and Keteyian, 1998)

Glycogen Sparing

The diminished utilization of glycogen that results when other fuels are available  (and are used) for activity; if, for instance, fat is used to a greater extent than usual, glycogen is “spared”; glycogen will thus be available longer before ultimately being depleted (Foss and Keteyian, 1998)


            Formation of glycogen from glucose (Marieb, 1998)


            Breakdown of glycogen from glucose (Marieb, 1998)


            A lipid with one or more covalently attached sugars (Marieb, 1998)


            Breakdown of glucose to pyruvic acid – an anaerobic process (Marieb, 1998)

Goal Setting

Described as a process whereby progressively challenging standards of performance are pursued with a defined criterion of task performance that increases the likelihood of perceived success (Baechle & Earle, 2000)

Golgi Tendon Organs

Proprioceptors located in tendons, close to the point of skeletal muscle insertion; important to smooth onset and termination of muscle contraction (Marieb, 1998)


            Sex hormones, primarily androgens, secreted by the adrenal cortex (Marieb, 1998)


            Gonad-stimulating hormones produced by the anterior pituitary (Marieb, 1998)


The ability of muscles to produce forces of varying strength; from very light to maximal force or tension (Foss and Keteyian, 1998)

Graded Muscle Response

Variations in the degree of muscle contraction by changing either the frequency or strength of the stimulus (Marieb, 1998)

Graded Potential

A local change in membrane potential that varies directly with the strength of the stimulus, and declines with distance (Marieb, 1998)

Ground Substance

Gel-like substance inside the cartilage matrix composed of glycoaminoglycans (Baechle & Earle, 2000)

Growth Cartilage

Cartilage located in the epiphyseal (growth) plate, joint surfaces, and apophyseal insertions of muscle-tendon units where bone formation occurs in children (Baechle & Earle, 2000)

Growth Hormone

Hormone that stimulates growth in general; produced in the anterior pituitary; also called somatotropin (STH) (Marieb, 1998)


A series of techniques in which the behavior of the learner is limited or controlled by various means to prevent errors (Schmidt & Lee, 1999)


            Male development of breasts; a side-effect of anabolic steroid abuse (Baechle & Earle, 2000)



The area in the center of the A-band where the cross-bridges are absent (Foss and Keteyian, 1998)


The acquired capability for moving; an unobservable internal state that underlies skilled performance (Schmidt & Lee, 1999)

Haldane Transformation

An equation allowing you to calculate the inspired air volume from expired air volume, or expired air volume from inspired air volume (Wilmore & Costill, 2004)

Half-Reaction Time

Method of estimating speed at which a chemical or physiological reaction or change occurs (e.g., in 30 seconds one-half of fast oxygen recovery component is completed) (Foss and Keteyian, 1998)

HDL Cholesterol

That portion of total plasma cholesterol that is transported or carried by high-density lipoproteins, higher levels of which carry an inverse relationship to the development of atherosclerosis (Foss and Keteyian, 1998)

Heart Attack

The blocking of blood flow to a portion of the heart muscle; also called myocardial infarction (Foss and Keteyian, 1998)

Heart Block

Impaired transmission of impulses from atrium to ventricle resulting in dysrhythmia (Marieb, 1998)

Heart Murmur

            Abnormal heart sound (usually resulting from valve problems) (Marieb, 1998)

Heart Rate

            The heart’s rate of pumping (Baechle & Earle, 2000)

Heart Rate Reserve

The difference between the resting heart rate and the maximal heart rate (Foss and Keteyian, 1998)

Heart Rate Recovery Period

The time it takes for heart rate to return to the resting rate following exercise (Wilmore & Costill, 2004)


            A form of energy (Foss and Keteyian, 1998)

Heat Cramps

            Painful muscular contractions caused by prolonged exposure to environmental heat

Heat Exhaustion

A condition of fatigue caused by prolonged exposure to environmental heat; may be associated with headache, nausea, and vomiting (Foss and Keteyian, 1998)

Heat Stroke

A disorder caused by overexposure to heat and characterized by high body (rectal) temperature, hot dry skin (usually flushed), and unconsciousness; it can be fatal (Foss and Keteyian, 1998)

Heavy-Chain Myosin Proteins

Heavy polypeptide chains composed of a head (motor domain) which contains ATP and actin binding sites and a tail region to which the light chains are attached (Baechle & Earle, 2000)

Helper T Cell

Type of T lymphocyte that orchestrates cellular immunity by direct contact with other immune cells and by releasing chemicals called lymphokines; also helps to mediate the humoral response by interacting with B cells (Marieb, 1998)


            The percentage of erythrocytes to total blood volume (Marieb, 1998)


            Mass of clotted blood that forms at an injured site (Marieb, 1998)


            Blood cell formation; hemopoiesis (Marieb, 1998)


            Discharge of blood into urine (Foss and Keteyian, 1998)


            Iron-containing pigment that is essential to oxygen transport by hemoglobin (Marieb, 1998)


A relative (not absolute) increase in the cellular content per unit of blood volume, resulting from a reduction in plasma volume (Wilmore & Costill, 2004)


            Bone marrow cell that gives rise to all the formed elements of blood (Marieb, 1998)


An increase in blood plasma resulting in a dilution of the blood’s cellular contents (Wilmore & Costill, 2004)


            The study of the physical laws governing blood flow (Foss and Keteyian, 1998)


            Oxygen-transporting component of erythrocytes (Marieb, 1998)

Hemoglobin Saturation

            The amount of oxygen bound by each molecule of hemoglobin (Wilmore & Costill, 2004)


            Rupture of erythrocytes (Marieb, 1998)


            Loss of blood from the vessels by flow through ruptured walls; bleeding (Marieb, 1998)


            Stoppage of bleeding (Marieb, 1998)

Henry’s Law

The amount of gas that a fluid will absorb under pressure varies in direct proportion to the partial pressure of the gas (Foss and Keteyian, 1998)


Abnormal protrusion of an organ or a body part through the containing wall of its cavity (Marieb, 1998)


The process in which specific events do not occur simultaneously or asynchronously, but rather in a complex sequence of distinct steps or actions, each of which lays the foundation for the next one (Siff, 2003)

Hick’s Law

A mathematical statement that choice reaction time is linearly related to the Log2 of the number of stimulus-response alternatives, or to the amount of information that must be processed in order to choose a response (Schmidt & Lee, 1999)

Hierarchal Control Model

The idea that with practice, the control of the response shifts systematically from attention-demanding higher levels to less attention-demanding motor program levels (Schmidt & Lee, 1999)

High-Density Lipoprotein (HDL)

A cholesterol carrier regarded as a scavenger; theorized to remove cholesterol from the arterial wall and transport it to the liver to be metabolized (Wilmore & Costill, 2004)

High-Energy Phosphogens

Includes ATP, ADP, and CP – all of which contain one or two high-energy phosphate bonds that can be split to liberate usable energy (Foss and Keteyian, 1998)

Hill’s Equation for Muscle Contraction

Establishes the functional connection between the force being exerted (F) and the maximal speed of muscular contraction (V) under isotonic conditions, in which case the speed of muscular contraction diminishes hyperbolically as the load increases; (Fo) is maximal strength, a and b are constants;  (F + a)(V +b) = (Fo + a) (Siff, 2003)

Hilton’s Law

Any nerve serving a muscle producing movement at a joint also innervates the joint itself and the skin over the joint (Marieb, 1998)


            A state of body equilibrium or stable internal environment of the body (Marieb, 1998)

Hooke’s Law

            Elongation of an elastic tissue is directly proportional to applied force (Siff, 2003)




Steroidal or amino acid-based molecules released to the blood that act as chemical messengers to regulate specific body functions (Marieb, 1998)

Hormone Receptor

A region of the membranes of target cells that is specific to and can react with only one hormone; analogous to a lock and key mechanism (Foss and Keteyian, 1998)

Hormone Receptor Complex

Formed when a hormone binds with its receptor; this unit undergoes a conformational shift and it activates whereupon it binds to the cell’s nucleus to expose transcriptional units that code for the synthesis of specific proteins (Baechle & Earle, 2000)

Human Growth Hormone (HGH)

            See Growth Hormone


            Pertaining to the moisture in the air (Foss and Keteyian, 1998)

Humoral Immune Response

Immunity conferred by antibodies present in blood plasma and other body fluids (Marieb, 1998)

Hyaline Cartilage

The most abundant cartilage type in the body; provides firm support with some pliability (Marieb, 1998)

Hydraulic Pressure

The force per unit area resulting from a vertical column of water of a certain height (Foss and Keteyian, 1998)

Hydrogen Bond

Weak bond in which a hydrogen atom forms a bridge between two electron-hungry atoms; an important intramolecular bond (Marieb, 1998)

Hydrogen Ion (H+)

A hydrogen atom minus its electron and therefore carrying a positive charge (i.e., a proton) (Marieb, 1998)


Refers to molecules, or portions of molecules, that interact with water and charged particles (Marieb, 1998)


Refers to molecules, or portions of molecules, that interact only with nonpolar molecules (Marieb, 1998)

Hydrostatic Pressure

            Pressure of fluid in a system (Marieb, 1998)

Hydrostatic Weighing

A method of measuring body volume in which a person is weighed while submerged underwater; the difference between the scale weight on land and the underwater weight (corrected for water density) equals body volume; this value must be further corrected to account for any air tapped in the lungs and other parts of the body (Wilmore & Costill, 2004)


Proteins added to the bone matrix that become mineralized as calcium phosphate crystals (Baechle & Earle, 2000)


Hydroxyl Ion (OH-)

An ion liberated when a hydroxide (a common inorganic base) is dissolved in water (Marieb, 1998)

Hyperbaric Environment

An environment, such as that underwater, involving high atmospheric pressure (Wilmore & Costill, 2004)


            High carbon dioxide levels in the blood (Marieb, 1998)


            An increase in blood flow into a tissue or organ; congested with blood (Marieb, 1998)


Term used to describe hormones such as glucagons that elevate blood glucose level (Marieb, 1998)


            High levels of insulin in the blood (Wilmore & Costill, 2004)


            Increase sodium concentration in the blood (Foss and Keteyian, 1998)

Hyperoxic Breathing

Breathing oxygen-enriched gas mixtures during rest periods or following exercise; may positively affect some aspects of exercise performance but remains controversial (Baechle & Earle, 2000)


Accelerated growth of tissue, e.g., in anemia, the bone marrow produces red blood cells at a faster rate (Marieb, 1998)


An overshoot of the repolarization process so that the cell membrane potential goes below the normal resting level (Foss and Keteyian, 1998)


Deeper and more vigorous breathing, but with unchanged respiratory rate, as during exercise (Marieb, 1998)


High blood pressure; usually defined as a systolic pressure of 140 mmHg or higher or a diastolic pressure of 90 mmHG or higher (Marieb, 1998) (Wilmore & Costill, 2004)


Elevated body temperature; anything above a person’s normal resting body temperature (Wilmore & Costill, 2004)


            Excessive, above normal, tone or tension (Marieb, 1998)

Hypertonic Solution

A solution that has a higher concentration of nonpenetrating solutes than the references cell; having greater osmotic pressure than the reference solution (blood plasma or interstitial fluid) (Marieb, 1998)


Increase in size of a tissue or organ independent of the body’s general growth (Marieb, 1998)



Hypertrophy Training Phase

A phase of strength training during general physical preparation intended to increase functional muscle bulk (Siff, 2003)


            Increased depth and rate of breathing (Marieb, 1998)


            An increased blood volume (Foss and Keteyian, 1998)


An induced state of hypersuggestibility in which positive suggestions relating to an athlete’s performance potential can be planted in the subconscious mind (Baechle & Earle, 2000)

Hypobaric Environment

An environment, such as that at high altitude, involving low atmospheric pressure (Wilmore & Costill, 2004)


            Low carbon dioxide levels in the blood (Marieb, 1998)


Term used to describe hormone such as insulin that decrease blood glucose level (Marieb, 1998)


            Abnormally low concentrations of sodium ions in extracelluar fluid (Marieb, 1998)


Another name for the pituitary gland; made up of the anterior lobe, called the adenohypophysis, and the posterior lobe, called the neurohypophysis (Foss and Keteyian, 1998)


            Low blood pressure (Marieb, 1998)


That portion of the brain that exerts control over visceral activities, water balance, body temperature and sleep (Foss and Keteyian, 1998)


            An abonormally low (less than 35ºC) body temperature (Foss and Keteyian, 1998)


            Below normal tone or tension (Marieb, 1998)

Hypotonic Solution

A solution that is more dilute (containing fewer nonpenetrating solutes) than the reference cell; cells placed in hypotonic solutions plump up rapidly as water rushes into them (Marieb, 1998)


            Decreased depth and rate of breathing (Marieb, 1998)


            Condition in which inadequate oxygen is available to tissues (Marieb, 1998)

Hypoxic Vasoconstriction

The constriction of blood vessels in response to low levels of oxygen (Wilmore & Costill, 2004)




The area of a myofibril containing actin and bisected by a Z line (Foss and Keteyian, 1998)

Ideal Performance State

A state of optimal psychological and physiological efficiency in which the athlete employs only the amount of psychic and physical energy required to perform the task well (Baechle & Earle, 2000)

Immune System

A functional system whose components attack foreign substances or prevent their entry into the body (Marieb, 1998)


Ability of the body to resist many agents (both living and nonliving) that can cause disease; resistance to disease (Marieb, 1998)


Ability of the body’s immune cells to recognize (by binding) specific antigens; reflects the presence of plasma membrane-bound receptors (Marieb, 1998)

Impact Plyometrics

A type of plyometric training in which the concentric rebound is stimulated by contact with a surface or an object (such as depth jumps) (Siff, 2003)

Impaired Fasting Glucose

A plasma glucose level of between 110 and 125 mg/dl following an 8-hour fast (Wilmore & Costill, 2004)

Imperfection Training

Training to give an athlete the ability to cope with unexpected and sub-optimal conditions; training in imperfect conditions so as to prepare the athlete to prevent injury during unexpected conditions within sport (Siff, 2003)


            The product of the magnitude of a torque and its time of application (Hamill & Knutzen 2003)

Impulse-Momentum Relationship

The relationship stating that the impulse is equal to the change in momentum (Hamill & Knutzen 2003)

Impulse-Timing Model

A model of motor programming in which movement trajectory is controlled by impulses that determine the amount and timing of applied forces (Schmidt & Lee, 1999)

Impulse-Variability Theory

A theory of rapid actions in which the variability in the muscular impulses leads directly to the variations or errors in movement control (Schmidt & Lee, 1999)

Impulsive Training

            Training with explosive reactive methods; see Plyometrics (Siff, 2003)

In Vitro

            In a test tube, glass, or artificial environment (Marieb, 1998)

In Vivo

            In the living body (Marieb, 1998)

Index of Difficulty (ID)

In Fitt’s Law, the Log2 (2A/W) or the theoretical “difficulty” of movement (Schmidt & Lee, 1999)

Indirect Calorimetry

A method of estimating energy expenditure by measuring respiratory gases (Wilmore & Costill, 2004)

Individual Differences

            Stable differences among individuals on some variable or task (Schmidt & Lee, 1999)

Individual Differences of Learning

Differences between or among individuals in the amount or rate of acquisition of skills (Schmidt & Lee, 1999)

Individualization Principle of Training

Training which suits one athlete may not necessarily suit another; training programs must be designed for individual athletes based upon individual peculiarities and requirements (Siff, 2003)


            Having no action (Foss and Keteyian, 1998)

Inertial Force

Additional force outside of gravity, such as a barbell or weight stack, that when accelerated exerts force upon the lifter (Baechle & Earle, 2000)

Inertial Training

Training in which strength is directed against the inertia of a load; two means of inertial training include the application of force against a horizontal wheel or suspended load or by spinning a heavy flywheel ergometer (Siff, 2003)


            The first year of life (Wilmore & Costill, 2004)


            Region of dead, deteriorating tissue resulting from a lack of blood supply (Marieb, 1998)

Inferior (Caudal)

            Pertaining to a position near the tail end of the long axis of the body


A nonspecific defensive response of the body to tissue injury; includes dilation of blood vessels and an increase in vessel permeability; indicated by redness, heat, swelling, and pain (Marieb, 1998)


            The content of a message that serves to reduce uncertainty (Schmidt & Lee, 1999)

Information-Processing Viewpoint

The study of movement in which the human is viewed as a processor of information, focusing on storage, coding, retrieval, and transformation of information (Schmidt & Lee, 1999)


            Pertaining to the groin region (Marieb, 1998)

Inherent Feedback

That feedback normally received in the conduct of a particular task (also called intrinsic feedback) (Schmidt & Lee, 1999)

Inhibiting Factors

Hormones transmitted from the hypothalamus to the anterior pituitary that inhibit release of some other hormones (Wilmore & Costill, 2004)



Inhibitory Postsynaptic Potential (IPSP)

A transient decrease in electrical potential (hyperpolarization) in a postsynaptic neuron from its resting membrane potential (Foss and Keteyian, 1998)

Initial Adjustment

Woodworth’s term for the initial open-loop portion of an aiming movement (Schmidt & Lee, 1999)

Initial Conditions

A construct in schema theory; the nature of the task and environment prior to the production of a movement (Schmidt & Lee, 1999)


            Supply of nerves to a body part (Marieb, 1998)

Inorganic Compound

Chemical substances that do not contain carbon, including water, salts, and many acids and bases (Marieb, 1998)

Inorganic Phosphate (Pi)

Simple form of phosphorus not in association with carbon, which would make it organic; a by product of ATP when it is split to ADP and Pi and used in resynthesizing ATP in the process of oxidative-phosphorylation (Foss and Keteyian, 1998)


Force of myocardial contraction; a shift in the Frank-Starling curve to the right or to the left (Foss and Keteyian, 1998)


A coordination pattern in which two movement components oscillate in 0º relative phase (Schmidt & Lee, 1999)


            Movable attachment of a muscle (Marieb, 1998)


The active process involving the diaphragm and the external intercostal muscles that expands the thoracic dimensions and thus the lungs; the expansion decreases pressure in the lungs, allowing outside air to rush in (Wilmore & Costill, 2004)

Inspiratory Capacity (IC)

            Maximal volume of air inspired from resting expiratory level (Foss and Keteyian, 1998)

Inspiratory Reserve Volume (IRV)

            Maximal volume of air inspired from end-inspiration (Foss and Keteyian, 1998)


A hormone that enhances the carrier-mediated diffusion of glucose into tissue cells, thus lowering blood glucose levels (Marieb, 1998)

Insulin-Dependent Diabetes Mellitus (IDDM)

One of two major categories of diabetes mellitus that is caused by the inability of the pancreas to produce sufficient insulin as a result of failure of the beta-cells in the pancreas; this is also known as type-I diabetes (Wilmore & Costill, 2004)

Insulin Resistance

            A deficient target cell response to insulin (Wilmore & Costill, 2004)

Insulin Sensitivity

An index of the effectiveness of a given insulin concentration on the disposal of glucose (Wilmore & Costill, 2004)


The process by which the nervous system processes and interprets sensory input and makes decisions about what should be done at each moment (Marieb, 1998)

Intensive Methods

            Strength training involving heavy loads and low volume (Siff, 2003)

Intercalated Discs

            Gap junctions connecting muscle cells of the myocardium (Marieb, 1998)

Intercept (a)

One of the constants for linear empirical equations; the value on the Y-axis when X is zero (Schmidt & Lee, 1999)

Interference Theory

A theory that forgetting is caused by interference from other learned materials (Schmidt & Lee, 1999)

Intermittent Work

Exercises performed with alternate periods of relief, as opposed to continuous work (Foss and Keteyian, 1998)

Intermuscular Coordination

Involves the synchronization or sequencing of actions between different muscle groups wihc are producing any given joint movements (Siff, 2003)

Internal Respiration

Exchange of gases between blood and tissue fluid and between tissue fluid and cells (Marieb, 1998)

Internal Work

The total work done resulting from the motion of all of the body’s segments (Hamill & Knutzen 2003)

Interneuron (Internuncial Neuron)

A nerve cell located between afferent (sensory) and efferent (motor) nerve cells; it acts as a “go-between” between incoming and outgoing impulses; neurons originating and terminating wholly within the spinal cord that connect various segments of it; some are thought to be involved in the spinal generators (Foss and Keteyian, 1998) (Schmidt & Lee, 1999)

Interstitial Cells (Leydig Cells)

Cells located in the loose connective tissue surrounding the seminiferous tubules; they produce androgens (most importantly testosterone), which are secreted into the surrounding interstitial fluid (Marieb, 1998)

Interstitial Fluid

            Fluid between the cells (Marieb, 1998)

Interstitial Lamellae

Incomplete lamellae that lie between intact osteons, filling the gaps between forming osteons, or representing the remnants of an osteon that has been cut through by bone remodeling (Marieb, 1998)

Intertrial Interval

The interval of time between one movement and the next in the knowledge of results paradigm (Schmidt & Lee, 1999)

Interval Sprinting

A method of training whereby an athlete might alternately sprint 50 m and job 60 m for distances of 4 to 5 km (Foss and Keteyian, 1998)

Interval Training

A system of physical conditioning in which the body is subjected to short but regularly repeated periods of work stress interspersed with adequate periods of relief (Foss and Keteyian, 1998)

Intervertebral Discs

            Discs of fibrocartilage between vertebrae (Marieb, 1998)

Intracapsular Ligament

Ligament located within and separate from the articular capsule of a synovial joint (Marieb, 1998)

Intracellular Fluid

            Fluid within a cell (Marieb, 1998)

Intrafusal Fibers

            Muscle cells (fibers) that house the muscle spindles (Foss and Keteyian, 1998)

Intramuscular Coordination

The control of muscle tension by activating or deactivating certain numbers of fibers (number encoding), modifying the firing rate of active fibers (rate encoding), and the synchronization or sequencing of firing of the different types of muscle fibers (pattern encoding) (Siff, 2003)

Intramuscular Glycogen

Complex carbohydrate stored within muscle cells; the glucose subunits are used as a ready source of energy for muscle metabolism (Foss and Keteyian, 1998)

Intrinsic Motivation

A desire to be competent and self-determining; the athlete is a self-starter and does not require external motivation to have a desire to compete (Baechle & Earle, 2000)

Invariant Characteristic

The relationship between joint position and joint torque established by the central nervous system (Schmidt & Lee, 1999)

Inverse Dynamics

An analytical approach calculating forces and moments based on the accelerations of the object (Hamill & Knutzen 2003)

Inverted-U Theory

Arousal facilitates performance up to an optimal level, beyond which further increases in arousal are associated with reduced performance; a description of the relationship between arousal and performance that resembles an inverted U when graphed (Baechle & Earle, 2000)

Involuntary Muscle

            Muscles not ordinarily under control of will (Marieb, 1998)

Involuntary Nervous System

            The autonomic nervous system (Marieb, 1998)


            Atom with a positive or negative electric charge (Marieb, 1998)

Ionic Bond

            Chemical bond formed by electron transfer between atoms (Marieb, 1998)


            Situated on the same side (Marieb, 1998)





A mineral found in the heme groups of red blood cells and tin the cytochromes of the mitochondrion; very important to oxygen transport, metabolism, and energy levels (Foss and Keteyian, 1998)


            Ability to respond to stimuli (Marieb, 1998)


            Local decrease in blood supply (Marieb, 1998)


Proteins that have the same basic make-up but also slight modifications that alter their function (e.g., in muscle both heavy- and light-chain myosin exist) (Foss and Keteyian, 1998)

Isokinetic Muscle Action

Muscle action in which the tension developed by the muscle while shortening at a constant speed is theoretically maximal over the full range of motion (Foss and Keteyian, 1998)

Isometric Muscle Action

Muscle action in which the muscle does not shorten (the load is too heavy) but internal tension increases (Marieb, 1998)

Isotonic Contraction

Contraction in which muscle tension remains constant and the muscle shortens (Marieb, 1998)

Isotonic Solution

A solution with a concentration of nonpenetrating solutes equal to that found in the reference cell (Marieb, 1998)


Joint (articulation)

            The junction of two or more bones (Marieb, 1998)

Joint Kinesthetic Receptor

            Receptor that provides information on joint position and motion (Marieb, 1998)


Karvonen Method

The calculation of training heart rate by adding a given percentage of the maximal heart rate by adding a given percentage of the maximal heart rate reserve to the resting heart rate; this method gives an adjusted heart rate that is approximately equivalent to the desired percentage of VO2 max (Wilmore & Costill, 2004)

Ketones (Ketone Bodies)

            Fatty acid metabolites; strong organic acids (Marieb, 1998)


            Abnormal condition during which an excess of ketone bodies is produced (Marieb, 1998)

Killer T Cell

            Cytotoxic T cell (Marieb, 1998)

Kilocalories (kcal)

            See Calorie

Kilogram-Meters (kg-m)

            A unit of work (Foss and Keteyian, 1998)

Kilojoules (kJ)

            A unit of energy (Foss and Keteyian, 1998)

Kinematic Feedback

Feedback about the movement characteristics or movement pattern produced (Schmidt & Lee, 1999)


Scientific study of human movement; includes such aspects of study as exercise physiology, motor learning/control, and biomechanics (Foss and Keteyian, 1998)

Kinesthesis (Kinesthetic Sense)

            Awareness of where the body and its components are in space and time (Siff, 2003)

Kinetic Energy

The energy of motion or movement, e.g., the constant movement of atoms, or the push given to a swinging door that sets it into motion (Marieb, 1998)

Kinetic Feedback

            Feedback about the force characteristics of a movement (Schmidt & Lee, 1999)

Knowledge of Performance (KP)

Augmented feedback related to the nature of the movement produced (Schmidt & Lee, 1999)

Knowledge of Results (KR)

Augmented feedback related to the nature of the result produced in terms of the environmental goal (Schmidt & Lee, 1999)

KR Delay

The interval between the production of a movement and the presentation of KR (Schmidt & Lee, 1999)

Krebs Cycle

Aerobic metabolic pathway occurring within mitochondria, in which food metabolites are oxidized and CO2 is liberated, and coenzymes are reduced (Marieb, 1998)


            A rounded spine, as seen in the thoracic spine (Baechle & Earle, 2000)



A substance important for fatty acid metabolism because it assists in the transfer of fatty acids from the cytosol (the fluid portion of the cytoplasm, exclusive organelles) across the inner mitochondrial membrane for beta-oxidation (Wilmore & Costill, 2004)


An essential amino acid that has been proposed to increase aerobic endurance performance through its effects on the central nervous system; it theoretically acts as an analgesic and delays fatigue (Wilmore & Costill, 2004)

Lactacid Oxygen Debt

That portion of the recovery oxygen used to remove accumulated lactic acid from the blood following exercise; the slow recovery phase (Foss and Keteyian, 1998)


            The salt of lactic acid (Baechle & Earle, 2000)

Lactate Dehydrogenase (LDH)

A key glycolytic enzyme involved in the conversion of pyruvate to lactate (Wilmore & Costill, 2004)

Lactate Threshold

The point during exercise where a nonlinear increase in blood lactate occurs (Foss and Keteyian, 1998)

Lactic Acid

            Product of anaerobic metabolism, especially in muscle (Marieb, 1998)

Lactic Acid System (LA System)

An anaerobic energy system in which ATP is manufactured when glucose (sugar) is broken down to lactic acid; high-intensity efforts requiring 1 to 3 minutes before energy (ATP) is primarily drawn from this system; more commonly referred to as anaerobic glycolysis (Foss and Keteyian, 1998)


A small space, cavity, or depression; lacunae in bone or cartilage are occupied by cells (Marieb, 1998)


            A layer, such as of bone matrix in Haversian Systems of compact bones (Marieb, 1998)


A thin layer or flat plate; the portion of a vertebra between the transverse process and the spinous process (Marieb, 1998)

Latent Period

            Period of time between stimulation and the onset of muscle contraction (Marieb, 1998)


            Away from the midline of the body (Marieb, 1998)

Law of Practice

The common finding that the log of the performance measure tends to change linearly with the log of the amount of practice (Schmidt & Lee, 1999)

LDL Cholesterol

That portion of total plasma cholesterol that is transported or carried by low-density lipoproteins, higher levels of which carry a direct relationship to the development of atherosclerosis (Foss and Keteyian, 1998)

Lead-Up Tasks

Certain tasks or activities that are typically presented to prepare learners for a more important or more complex task or activity (Schmidt & Lee, 1999)

Lean Body Mass (Weight)

            The body weight minus the weight of the body fat (Foss and Keteyian, 1998)


A set of internal processes associated with practice or experience leading to relatively permanent changes in the capability for skill (Schmidt & Lee, 1999)

Learning Curve

A label sometimes applied to the performance curve, in the belief that the changes in performance mirror changes in learning (Schmidt & Lee, 1999)

Learning Score

A difference score, computed as the difference between the initial and final levels of performance; sometimes used in computing the changes in performance as a result of practice (Schmidt & Lee, 1999)

Learning Variable

            An independent variable that affects learning (Schmidt & Lee, 1999)

Left Bundle Branch

Part of the conduction system of the heart; receives the impulse from the AV bundle and passes it along into the Purkinje Fibers (Baechle & Earle, 2000)

Length-Tension Relationship

The amount of force that a muscle can exert is related to its length; peak force production is usually seen at resting length or slightly greater than resting length (Baechle & Earle, 2000)


White blood cells; formed elements involved in body protection that take part in inflammatory and immune responses (Marieb, 1998)


An increase in the number of leukocytes (white blood cells); usually the result of a microbiological attack on the body (Marieb, 1998)


            Abnormally low white blood cell count (Marieb, 1998)


            The production of white blood cells (Marieb, 1998)


A rigid or semirigid body that, when subjected to a force whose line of action does not pass through its pivot point, exerts force on any object impeding its tendency to rotate; a mechanism for doing work that consists of a fulcrum and two eccentric forces (Baechle & Earle, 2000) (Hamill & Knutzen 2003)

Lever System

Consists of a lever (bone), effort (muscle action), resistance (weight of object to be moved) and fulcrum (joint) (Marieb, 1998)


            Band of regular fibrous tissue that connects bones (Marieb, 1998)


            Pertaining to a straight line (Foss and Keteyian, 1998)


Organic compound formed of carbon, hydrogen, and oxygen; examples are fats and cholesterol (Marieb, 1998)


            The process of converting protein into fatty acids (Wilmore & Costill, 2004)


            The breakdown of stored fats into glycerol and fatty acids (Marieb, 1998)

Lipoprotein Lipase

The enzyme that breaks down triglycerides to free fatty acids and glycerol, allowing the free fatty acids to enter the cells for use as a fuel or for storage (Wilmore & Costill, 2004)


            The proteins that carry the blood lipids (Wilmore & Costill, 2004)

Loadless Training

A training technique involving maximal voluntary muscle contractions against little or no resistance (Siff, 2003)

Local Angular Momentum

The angular momentum of a body segment about its own center of mass (Hamill & Knutzen 2003)

Lock-And-Key Theory

Theory stating that the receptor is the lock and the hormone is the key (Baechle & Earle, 2000)

Log2 (N)

            The power to which the base 2 must be raised to achieve N (Schmidt & Lee, 1999)


            The length of a person’s life (Wilmore & Costill, 2004)

Long-Loop Reflex

A stretch reflex with a latency of from 50 to 80 milliseconds, modified by instruction, and mediated in higher brain centers (Schmidt & Lee, 1999)

Long-Term Memory

A functionally limitless memory store for abstractly coded information, facts, concepts, and relationships; presumably storage for movement patterns (Schmidt & Lee, 1999)

Longitudinal Fiber Splitting

Development of new muscle fibers from existing ones as a result of intense chronic “weight training”; shown only in experimental animals (Foss and Keteyian, 1998)

Longitudinal Research Design

A research design in which subjects are tested initially and then one or more times later to directly measure changes over time resulting from a given intervention (Wilmore & Costill, 2004)

Longitudinal Tubules

Portions of the sarcoplasmic reticulum that run parallel to the muscle myofibrils and terminate in the outer vesicles (Foss and Keteyian, 1998)


            A slightly arched back as seen in the lumbar spine (Baechle & Earle, 2000)

Low-Density Lipoprotein (LDL)

A cholesterol carrier theorized to be responsible for depositing cholesterol in the arterial wall (Wilmore & Costill, 2004)

Lower Body (Gynoid) Obesity

Obesity that follows the typically female pattern of fat storage, in which fat is stored primarily on the lower body, particularly in the hips, buttocks, and thighs (Wilmore & Costill, 2004)


            Portion of the back between the thorax and the pelvis (Marieb, 1998)

Lumbar Vertebrae

The five vertebrae of the lumbar region of the vertebral column, commonly called the small of the back (Marieb, 1998)

Luteinizing Hormone (LH)

Anterior pituitary hormone that aids maturation of cells in the ovary and triggers ovulation in females; in males, causes the interstitial cells of the testis to produce testosterone (Marieb, 1998)


            Protein-containing fluid transported by lymphatic vessels (Marieb, 1998)

Lymphatic System

System consisting of lymphatic vessels, lymph nodes, and other lymphoid organs and tissues; drains excess tissue fluid from the extracellular space and provides a site for immune surveillance (Marieb, 1998)


Agranular white blood cell that arises from bone marrow and becomes functionally mature in the lymphoid organs of the body (Marieb, 1998)


Proteins involved in cell-mediated immune responses that enhance immune and inflammatory responses (Marieb, 1998)


M-Bridge (M-band)

That portion of the sarcomere where adjacent myosin filaments anchor to each other (Baechle & Earle, 2000)


Refers to a single competitive season and is comprised of mesocycles occupying a period of many months (Siff, 2003)

Macroelectric Cellular Stimulation (MACS)

Electric current exceeding one milliamp applied to the body as a physiological stressor which in the short term causes the typical alarm response described by Selye (Siff, 2003)


            The minerals of which the body needs more than 100 mg per day (Wilmore & Costill, 2004)


            Large, complex molecules containing from 100 to over 10,000 amino acids (Marieb, 1998)

Magnet Effect

Identified by von Holst as the tendency of one effector’s rhythmic oscillation to become interdependent with another oscillating limb (Schmidt & Lee, 1999)

Maintenance Tendency

Identified by von Holst as the tendency of one effector to maintain an independent rhythmic oscillation while another effector is oscillating (Schmidt & Lee, 1999)


            A so-called recreational drug that is generally ergolytic (Wilmore & Costill, 2004)


A side-effect for women abusing anabolic steroids; the adoption of male physical characteristics including upper body muscularity, decreased body fat from the breasts and hips, deepening of the voice, cessation of menstrual cycles, and increased facial hair (Baechle & Earle, 2000)

Masking Agent

Such as diuretics, dilute urine specimens and make it difficult to obtain a positive test for another banned substance, such as anabolic steroids; labs can now test for masking agents as well as concentrate the effected urine specimens and adjust the pH so a proper drug screen can be performed (Baechle & Earle, 2000)

Maslow’s Hierarchy of Needs

A model of human needs developed by Abraham Maslow; the most basic human needs (such as physiological and survival needs) need to be satisfied before subsequent needs (such as social needs) begin to exert influence on a person (Siff, 2003)      


The quantity of matter of an object that is reflected in its inertia (SI unit: kilogram) (Foss and Keteyian, 1998)

Massed Practice

A sequence of practice and rest periods in which the rest time is much less than the practice time (Schmidt & Lee, 1999)


The process by which the body takes on the adult form and becomes fully functional; it is often defined by the system or function being considered (Wilmore & Costill, 2004)

Maximal Aerobic Power

            See Maximal Oxygen Consumption

Maximal Expiratory Ventilation

The highest ventilation that can be achieved during exhaustive exercise (Wilmore & Costill, 2004)

Maximal Heart Rate Reserve

            The difference between maximal heart rate and resting heart rate (Wilmore & Costill, 2004)

Maximal Oxygen Consumption (max VO2)

The maximal rate at which oxygen can be consumed per minute; the power or capacity of the aerobic or oxygen system (Foss and Keteyian, 1998)

Maximal Oxygen Uptake

The greatest amount of oxygen that can be used at the cellular level for the entire body (Baechle & Earle, 2000)

Maximal Plyometrics

A type of plyometric training in which low-repetition activities are done where the intensity of the depth jump or rebound exercise is such that maximal or near-maximal rebound tension is produced in the relevant muscles (Siff, 2003)

Maximum Heart Rate

The highest heart rate value attainable during an all-out effort to the point of exhaustion (Wilmore & Costill, 2004)

Maximum Strength

A measure of maximal voluntary isometric muscular force which can be produced without a time limit or a limit to the amount of weight lifted (Siff, 2003)

Maximum Voluntary Contraction (MVC)

The greatest force output that an individual can generate from a muscle group through only volitional control (Foss and Keteyian, 1998)

McCloy Method of Training

The use of a weight 50% of one’s 10RM for 10 repetitions, followed by a weight equal to one’s 10RM for 10 reps, and finally a load 75% of one’s 10RM for 10 reps (Siff, 2003)

Mean Arterial Pressure (MAP)

            The average blood pressure throughout the cardiac cycle (Baechle & Earle, 2000)

Mechanical Advantage (Power Lever)

Condition that occurs when the load is close to the fulcrum and the effort is applied far from the fulcrum; allows a small effort exerted over a relatively large distance to move a large load over a small distance; the ratio of the effort arm to the resistance arm of a lever (Marieb, 1998) (Hamill & Knutzen 2003)

Mechanical Disadvantage (Speed Lever)

Condition that occurs when the load is far from the fulcrum and the effort is applied near the fulcrum; the effort applied must be greater than the load to be moved (Marieb, 1998)

Mechanical Energy

The energy directly involved in moving matter; e.g., in bicycle riding, the legs provide the mechanical energy that moves the pedals (Marieb, 1998)

Mechanical Load

Stimulates bone and muscle growth; dependent upon the magnitude of the load (intensity, the rate (speed) of loading, the direction of the forces, and the volume of loading (repetitions) (Baechle & Earle, 2000)


Receptor sensitive to mechanical pressure such as touch, sound, or exerted by muscle contraction (Marieb, 1998)


            Toward the midline of the body (Marieb, 1998)

Medial Lemniscal System

The pathway to the cerebral cortex for discriminative touch, pressure, vibration, and conscious proprioception (Marieb, 1998)

Median (Midsagittal) Plane

            Specific sagittal plane that lies exactly in the midline (Marieb, 1998)

Medulla Oblongata

That portion or area of the brain continuous above with the pons and below with the spinal cord and containing the cardiorespiratory control area (Foss and Keteyian, 1998)


A thin layer of tissue that covers a surface or divides a space or organ (Foss and Keteyian, 1998)

Membrane Potential

            Voltage across the plasma membrane (Marieb, 1998)

Memory Cells

            Members of T cell and B cell clones that provide for immunologic memory (Marieb, 1998)

Memory Trace

A construct in Adams’s closed loop theory; a modest motor program for determining and initiating the movement (Schmidt & Lee, 1999)

Messenger RNA (mRNA)

Long nucleotide strands that reflect the exact nucleotide sequences of the genetically active DNA and carry the message of the latter (Marieb, 1998)


            The onset of menstruation (Foss and Keteyian, 1998)


            The monthly flow of blood from the genital tract of women (Foss and Keteyian, 1998)

Menstrual Cycle

The cycle of uterine changes, averaging 28 days and consisting of the menstrual (flow) phase, the proliferative phase, and secretory phase (Wilmore & Costill, 2004)

Menstrual Dysfunction

Disruption of the normal menstrual cycle; it includes oligomenorrhea, primary amenorrhea, and secondary amenorrhea (Wilmore & Costill, 2004)


            The process or an instance of discharging the meses (Foss and Keteyian, 1998)

Mental Imagery

A cognitive psychological skill in which the athlete uses all the senses to create a mental experience of an athletic performance (Baechle & Earle, 2000)

Mental Practice

A practice method in which performance on the task is imagined or visualized without overt physical practice (Schmidt & Lee, 1999)

Mesencephalic Preparation

A surgical preparation in which the spinal cord is cut at the mid-brain, essentially separating higher centers from the spinal cord (Schmidt & Lee, 1999)


Refers to a number of microcycles which serve as a recurring unit over a period of several weeks or months within a macrocycle (Siff, 2003)


A body type component characterized by a square body with hard, rugged, and prominent musculature (Foss and Keteyian, 1998)

MET (Metabolic Equivalent)

The amount of oxygen required per minute under resting, sitting conditions; it is approximately 3.5 mL of oxygen consumed per kilogram of body weight per minute (Foss and Keteyian, 1998)

Metabolic Rate

            Energy expended by the body per unit time (Marieb, 1998)

Metabolic Syndrome

A term that has been used to link coronary artery disease, hypertension, type II diabetes, and upper body obesity to insulin resistance and hyperinsulinemia; this syndrome has also been referred to as syndrome X and the civilization syndrome (Wilmore & Costill, 2004)

Metabolic System

A system of biochemical reactions that cause the formation of waste products (metabolites) and the manufacture of ATP; for example, the ATP-PC, anaerobic glycolysis, and oxygen systems (Foss and Keteyian, 1998)


            Sum total of the chemical reactions occurring in the body cells (Marieb, 1998)


            Any substance produced by a metabolic reaction (Foss and Keteyian, 1998)


Peripheral nerve endings primarily activated by metabolic changes (e.g., pH) in and around contracting skeletal muscle (Foss and Keteyian, 1998)


Refers to a state which persists until a disturbance happens to move it to another state of stability (Siff, 2003)


Refers to a number of training sessions which form a recurrent unit with a period of several days within a mesocycle (Siff, 2003)

Microelectric Cellular Stimulation (MICS)

            Electric current below one milliamp applied to the body for restorative purposes (Siff, 2003)


            The parallel arrangement of filaments within a collagen fiber (Baechle & Earle, 2000)


            Thin strands of the contractile protein actin (Marieb, 1998)


An environment in which the body experiences a reduced gravitational force (Wilmore & Costill, 2004)

Microminerals (Trace Elements)

            The minerals of which the body needs less than 100 mg per day (Wilmore & Costill, 2004)

Midsagittal (Medial) Plane

            Specific sagittal plane that lies exactly in the midline (Marieb, 1998)


            One thousandth of a mole (Foss and Keteyian, 1998)


Steroid hormone of the adrenal cortex that regulates mineral metabolism and fluid balance (Marieb, 1998)


            Inorganic chemical compounds found in nature; salts (Marieb, 1998)

Minimal Essential Strain (MES)

            The threshold stimulus that initiates new bone formation (Baechle & Earle, 2000)

Minimax Principle

Using the minimum effort to achieve the maximum results, preferably in the least amount of time (Siff, 2003)

Minute Ventilation

The amount of air inspired (Vi) or expired (Ve) in one minute; usually it refers to the expired amount (Foss and Keteyian, 1998)

Miometric Muscle Action

            See Concentric Muscle Action (Siff, 2003)


Cytoplasmic organelles responsible for ATP generation for cellular activities (Marieb, 1998)

Mitochondrial Oxidative Enzymes

            Oxidative enzymes located in the mitochondria (Wilmore & Costill, 2004)

Mixed Nerves

Nerves containing the processes of motor and sensory neurons; their impulses travel to and from the CNS (Marieb, 1998)


            Type of exercise (Wilmore & Costill, 2004)


            A technique for demonstrating the learning task (Schmidt & Lee, 1999)


A view of individual differences that organizes brain activities in terms of functions (such as timekeeping) rather than tasks (Schmidt & Lee, 1999)


The gram-molecular weight or gram-formula weight of a substance (Foss and Keteyian, 1998)


            Particle consisting of two or more atoms joined together by chemical bonds (Marieb, 1998)


See Torque (Hamill & Knutzen 2003)

Moment Arm

The perpendicular distance of the line of action of a force to the axis of rotation (Hamill & Knutzen 2003)

Moment of Force

            See Torque (Hamill & Knutzen 2003)

Moment of Inertia

            The resistance of a body to angular acceleration (Hamill & Knutzen 2003)


            Large single-nucleus white blood cell; agranular leukocyte (Marieb, 1998)


Chemical mediators that enhance the immune response; secreted by macrophages (Marieb, 1998)


            Literally, one sugar; building block of carbohydrates; e.g., glucose (Marieb, 1998)

Monosynaptic Stretch Reflex

A segmental reflex produced by stretch of a muscle and its spindles connecting monosynaptically with the alpha motorneurons of the same muscle; it has a latency of about 30 to 50 milliseconds in humans (Schmidt & Lee, 1999)

Monotonic Increase

            Continual increase without any decrease (Siff, 2003)


Fatty acids containing one double bond; generally do not exert an effect on cholesterol (Baechle & Earle, 2000)


            The form and structure of the body (Wilmore & Costill, 2004)


An internal state that tends to direct or energize the system toward a goal (Schmidt & Lee, 1999)

Motive To Achieve Success (MAS)

The desire to attain victory or success; an athlete with MAS tends to heighten effort in response to the challenge and not perceive any threat; playing to win (Baechle & Earle, 2000)

Motive To Avoid Failure (MAF)

The desire to protect one’s ego and self-esteem; an athlete with MAF may reduce effort because he or she fears failure and the threat to self-esteem, playing not to lose (Baechle & Earle, 2000)

Motor Areas

Functional areas in the cerebral cortex that control voluntary motor functions (Marieb, 1998)

Motor Behavior

An area of study stressing primarily the principles of human skilled movement generated at a behavior level of analysis (Schmidt & Lee, 1999)

Motor Control

An area of study dealing with the understanding of the neural, physical, and behavioral aspects of movement (Schmidt & Lee, 1999)

Motor Development

A field of study concerning the changes in motor behavior occurring as a result of growth, maturation, and experience (Schmidt & Lee, 1999)

Motor End Plates

Troughlike part of a muscle fiber’s sarcolemma that helps form the neuromuscular junction (Marieb, 1998)

Motor Engrams

Memorized motor patterns that are stored in the motor area of the brain (Foss and Keteyian, 1998)

Motor Learning

The process of programming the brain/central nervous system to be able to carry out specific movement tasks; a set of internal processes associated with practice or experience leading to relatively permanent changes in the capability for motor skill (Siff, 2003) (Schmidt & Lee, 1999)

Motor Memory

            The memory for movement or motor information (Schmidt & Lee, 1999)

Motor Nerves

Nerves that carry impulses leaving the brain and spinal cord, and destined for effectors (Marieb, 1998)

Motorneuron Pools

Collections of alpha motorneuron cell bodies in the gray matter of the spinal cord that serve motor units in the same or anatomically-related muscles (Schmidt & Lee, 1999)

Motor Program

An abstract representation that, when initiated, results in the production of a coordinated movement sequence (Schmidt & Lee, 1999)

Motor Reaction Time

The interval between the first change in EMG and the movement’s initiation (Schmidt & Lee, 1999)

Motor Unit

            A motor neuron and all the muscle cells it stimulates (Marieb, 1998)


            Changes in joint angles, the position of the entire body, or both (Schmidt & Lee, 1999)

Movement Outcome

A construct in schema theory; the result of the movement in the environment, usually signaled by intrinsic feedback or KR (Schmidt & Lee, 1999)

Movement Time (MT)

            The interval between the initiation of a movement and its termination (Schmidt & Lee, 1999)

Multiaxial Joint

A joint which allows movement about all three perpendicular axes that define space; as seen in the shoulder and hip ball-and-socket joints (Baechle & Earle, 2000)

Multiple Correlation

A statistical procedure in which the weightings of predictor variables are adjusted so that their sum correlates maximally with some criterion variable (Schmidt & Lee, 1999)

Multiple Motor Unit Summation

The varying of the number of motor units contracting within a muscle at any given time (Foss and Keteyian, 1998)


            A system that can exhibit stability in not one, but a variety of different states (Siff, 2003)


Muscle Bundle

            A fasciculus (Foss and Keteyian, 1998)

Muscle Buffering Capacity

The muscles’ ability to tolerate the acid that accumulates in them during anaerobic glycolysis (Wilmore & Costill, 2004)

Muscle Fiber

            A muscle cell (Marieb, 1998)

Muscle Force

Force generated by biochemical activity, or the stretching of noncontractile tissue that tends to draw the opposite ends of a muscle toward each other (Baechle & Earle, 2000)

Muscle Power

The product of the net muscle moment and the angular velocity of the joint (Hamill & Knutzen 2003)

Muscle Spindle (Neuromuscular Spindle)

            Encapsulated receptor found in skeletal muscle that is sensitive to stretch (Marieb, 1998)

Muscle Spindle Reflex

Discharge of impulses from muscle spindles due to stretch, which results in CNS reflex maintenance of active muscle tonus in the same muscles (Foss and Keteyian, 1998)

Muscle Strength

The force or tension that a muscle or group of muscles can exert against a resistance in one maximal effort (Foss and Keteyian, 1998)

Muscle Tension

            The force exerted by a contracting muscle on some object (Marieb, 1998)

Muscle Tone

Sustained partial contraction of a muscle in response to stretch receptor inputs; keeps the muscle healthy and ready to act (Marieb, 1998)

Muscle Twitch

            The response of a muscle to a single brief threshold stimulus (Marieb, 1998)

Muscle Wisdom

The process in which the activation discharge rate of alpha motor neurons is modulated by the central nervous system to optimize force production by skeletal muscle during sustained muscle action (Siff, 2003)

Muscular Dystrophy

            A group of inherited muscle-destroying diseases (Marieb, 1998)

Muscular Endurance

The ability of a muscle or muscle group to perform repeated contractions against a light load for an extended period of time (Foss and Keteyian, 1998)

Muscular System

The organ system consisting of the skeletal muscles of the body and their connective tissue attachments (Marieb, 1998)

Myelin Sheath

            Fatty insulating sheath that surrounds all but the smallest nerve fibers (Marieb, 1998)


            The process of acquiring a myelin sheath (Wilmore & Costill, 2004)



Myocardial Infarction (MI)

Condition characterized by dead tissue areas in the myocardium; caused by interruption of blood supply to the area (Marieb, 1998)


            Layer of the heart wall composed of cardiac muscle (Marieb, 1998)


Rodlike bundle of contractile filaments (myofilaments) found in muscle cells (Marieb, 1998)


Filament that constitutes myofibrils consisting of two types: actin and myosin (Marieb, 1998)

Myogenic Factors

Substances found within muscle fibers that regulate the properties specific to the fiber type, such as contractile speed and power production during contraction (Foss and Keteyian, 1998)


            Oxygen-binding pigment in muscle (Marieb, 1998)


A graphic recording of mechanical contractile activity produced by an apparatus that measures muscle contraction (Marieb, 1998)

Myokinase (MK)

Enzyme found in muscle cells that catalyzes (speeds) the reformation of ATP in the presence of ADP


            One of the principle contractile proteins found in muscle (Marieb, 1998)


Myofibrillar adenosine triphosphatase; an enzyme found in myosin that catalyzes ATP degradation to ADP and Pi; a marker for muscle fiber contraction speed (Foss and Keteyian, 1998)

Myosin Heavy Chain (MHC)

A component of myosin that determines its contractile characteristics; occurs in three isoforms (type I, IIa, and IIx) (Siff, 2003)


Natural Killer (NK) Cells

Defensive cells that can lyse and kill cancer cells and virus-infected body cells before the immune system is activated (Marieb, 1998)


A giant protein that coextends with actin and appears to play a regulatory role in mediating actin and myosin interactions (Wilmore & Costill, 2004)


            Death of a cell or group of cells in contact with living tissue (Foss and Keteyian, 1998)

Needs Analysis

An assessment of factors that determine the specific training program appropriate for an individual (Wilmore & Costill, 2004)

Negative Energy Balance

A condition in which less energy (food) is taken in than is given off; body weight decreases as a result (Foss and Keteyian, 1998)


Negative Feedback Mechanism

A system of regulatory control where a change from normal is detected and an adjustment is effected until normal levels are reestablished (Foss and Keteyian, 1998)

Negative Transfer

The loss in capability for one task as a result of practice or experience in some other task (Schmidt & Lee, 1999)

Negative Work

Force times distance applied in the same direction as the pull of gravity assisted by gravity; the work done on a system when the loading torque is greater than the torque exerted by the muscle (Foss and Keteyian, 1998) (Hamill & Knutzen 2003)

Nerve Cell

            A neuron (Marieb, 1998)

Nerve Conduction Velocity

The speed of travel of nerve impulses along nerve axons or fibers; faster for large fibers and faster still for myelinated (insulated) ones (Foss and Keteyian, 1998)

Nerve Fiber

            Axon of a neuron (Marieb, 1998)

Nerve Impulse

            A self-propagating wave of depolarization; also called an action potential (Marieb, 1198)

Nerve Plexuses

Interlacing nerve networks that occur in the cervical, brachial, lumbar, and sacral regions and primarily serve the limbs (Marieb, 1998)

Nervous System

Fast-acting control system that triggers muscle contraction or gland secretion (Marieb, 1998)

Net Oxygen Cost

The amount of oxygen, above resting values, required to perform a given amount of work; also referred to as net cost of exercise (Foss and Keteyian, 1998)


Describes the close relationship of chemical substances that have both neural and hormone functions; some neurotransmitters have endocrine functions (Baechle & Earle, 2000)


The posterior lobe of the pituitary gland; so called because of its direct connection with the hypothalamus of the brain; secretes ADH and oxytocin (Foss and Keteyian, 1998)

Neuromuscular Efficiency

Refers to the skill with which one executes a given movement and relates to how efficiently and intensively one recruits muscle fibers in the appropriate muscle groups to produce the movement pattern accurately and powerfully (Siff, 2003)

Neuromuscular Junction

Region where a motor neuron comes into close contact with a skeletal muscle cell (Marieb, 1998)


Cell of the nervous system specialized to generate and transmit nerve impulses (Marieb, 1998)

Neuron Cell Body

            The biosynthetic center of a neuron; also called the perikaryon, or soma (Marieb, 1998)

Neuronal Pools

            Functional groups of neurons that process and integrate information (Marieb, 1998)


A class of neurotransmitters including beta-endorphins and enkephalins (which act as euphorics and reduce perception of pain) and gut-brain peptides (Marieb, 1998)


Chemical released by neurons that may, upon binding to receptors of neurons or effector cells, stimulate or inhibit them (Marieb, 1998)

Neutral Equilibrium

The state of a body in which the body will remain in a location if displaced from another location (Hamill & Knutzen 2003)

Neutral Fats

Consist of fatty acid chains and glycerol; also called triglycerides or triacylglycerols; commonly known as oils when liquid (Marieb, 1998)


Muscles counteracting the unwanted actions of other muscles by tending to produce opposite movements (Siff, 2003)


            Most abundant type of white blood cell (Marieb, 1998)

Nicotinamide Adenine Dinucleotide

An acceptor and carrier of hydrogen from various reaction sites in the cytosol and Krebs Cycle to the electron transport system (Foss and Keteyian, 1998)


A central nervous system stimulant found in tobacco products that is proposed to have ergogenic properties (Wilmore & Costill, 2004)

Nicotinic Receptors

Acetylcholine-binding receptors of all autonomic postganglionic neurons and skeletal muscle neuromuscular junctions (Marieb, 1998)

Nitrogen Balance

A monitor of daily protein balance; a positive nitrogen balance means that nitrogen intake from protein is equal to or slightly greater than nitrogen loss (Foss and Keteyian, 1998)

Nitrogen Narcosis

A condition caused by breathing air underwater at depths where the partial pressure of nitrogen is elevated, causing the central nervous system to experience a narcotic-like effect and leading to distortions in judgment and sometimes to serious injury or death; also known as rapture of the deep (Wilmore & Costill, 2004)

Nodes of Ranvier

Those areas on a myelinated nerve that are devoid of a myelin sheath (Foss and Keteyian, 1998)

Non-Functional Resistance Machines

Training machines that provide a useful supplementary role to free weight and functional machine training, but in general are unable to provide the same degree of multi-dimensional, full range neuromuscular and musculoskeletal training as free weights and functional machines (Siff, 2003)

Non-Impact Plyometrics

A type of plyometric training in which the concentric rebound is not stimulated by contact with a surface or object, but rather by the eccentric action of the muscles that produce a movement (such as a rapidly-retracted blow in boxing or martial arts) (Siff, 2003)

Non-Insulin-Dependent Diabetes Mellitus (NIDDM)

One of two major categories of diabetes mellitus that is caused by the ineffectiveness of insulin to facilitate the transport of glucose into the cells and is a result of insulin resistance; this is also known as type-II diabetes (Wilmore & Costill, 2004)

Nonessential Amino Acids

            The 11 or 12 amino acids that the body synthesizes (Wilmore & Costill, 2004)

Nonlinear Dynamics

A theory by Ilya Prigogine that maintains that order can occur spontaneously or by chance through a process of self-organization (Siff, 2003)


Individuals who show little or no improvement compared with others who undergo the same training program (Wilmore & Costill, 2004)

Nonshivering Thermogenesis

The stimulation of metabolism by the sympathetic nervous system to generate more metabolic heat (Wilmore & Costill, 2004)

Nonsteroid Hormones

Hormones derived from protein, peptides, or amino acids that cannot easily cross cell membranes (Wilmore & Costill, 2004)


A catecholamine (biogenic amine) neurotransmitter and adrenal medullary hormone, associated with sympathetic nervous system activation (Marieb, 1998)

Nuclear Bag Fibers

            Intrafusal muscle fibers which contain the primary muscle spindle receptors (Siff, 2003)

Nuclear Chain Fibers

            Intrafusal muscle fibers which contain the secondary muscle spindle receptors (Siff, 2003)

Nucleic Acid

            Class of organic molecules that includes DNA and RNA (Marieb, 1998)

Nutrient Density

Refers to the nutrients (vitamins, minerals, and protein) present per calorie of food (Baechle & Earle, 2000)


Chemical substances taken in via the diet that are used for energy and cell building (Marieb, 1998)

Nutritional Agents

            Nutritional substances proposed to have ergogenic benefits (Wilmore & Costill, 2004)



An excessive accumulation and storage of fatty tissue; greater than 20% above ideal body weight for size, age, and gender (Foss and Keteyian, 1998)


The aspect of measurement related to the extent to which two observers achieve the same score (Schmidt & Lee, 1999)


            Abnormally infrequent or scant menstruation (Wilmore & Costill, 2004).


One Repetition Maximum (1RM)

            See 1-RM

Onset of Blood Lactate Accumulation (OBLA)

A second increase in the rate of lactate accumulation noted at higher relative intensities of exercise; usually occurs when the concentration of blood lactate is near 4 mmol/L (Baechle & Earle, 2000)

Open-Loop System

A control system with preprogrammed instructions to an effector that does not use feedback information and error-detection processes (Schmidt & Lee, 1999)


A desired or target behavior; a clearly defined standard of performance (Baechle & Earle, 2000)

Operant Conditioning

A type of conditioning in which the response is strengthened or weakened by events that follow the response (Siff, 2003)

Operant Techniques

Methods for leaning in which certain behaviors are reinforced or rewarded, leading to an increase in the probability that they will occur again (Schmidt & Lee, 1999)


            To concretely specify a behavior so that it can be measured (Baechle & Earle, 2000)

Optimized Submovement Model

A view of the speed-accuracy trade-off that optimizes the duration of an initial impulse and, if necessary, one or more corrective impulses (Schmidt & Lee, 1999)

Oral Contraceptives

Drugs used for birth control and other medical purposes, which are believed by some female athletes to have ergogenic properties (Wilmore & Costill, 2004)


A part of the body formed of two or more tissues and adapted to carry out a specific function; e.g., the stomach (Marieb, 1998)

Organic Compound

Any compound composed of atoms (some of which are carbon) held together by covalent (shared electron) bonds (Marieb, 1998)


Pertaining to carbon-containing molecules, such as proteins, fasts, and carbohydrates (Marieb, 1998)


The living animal (or plant), which represents the sum total of all its organ systems working together to maintain life (Marieb, 1998)


Attachment of a muscle that remains relatively fixed during muscular contraction (Marieb, 1998)

Oscillatory Isometrics

An isometric training technique in which maximum tension can be produced voluntarily during sinusoidally pulsed brief isometric jerks at 5 Hertz (Siff, 2003)


The diffusion through a semipermeable membrane of a solvent such as water from a lower to a more concentrated solution (Foss and Keteyian, 1998)

Osmotic Pressure

            The force per unit area needed to stop osmosis (Foss and Keteyian, 1998)


            See Osteogenesis


            Bone-forming cells (Marieb, 1998)


            Large cells that resorb or break down bone matrix (Marieb, 1998)


            Mature bone cell (Marieb, 1998)


            The process of bone formation; also called ossification (Marieb, 1998)


            Unmineralized bone matrix (Marieb, 1998)


            Disorder in which bones are inadequately mineralized; soft bones (Marieb, 1998)


System of interconnecting canals in the microscopic structure of adult compact bone; unit of bone; also called Haversion system (Marieb, 1998)


A conditioned defined by having a bone mineral density between –1 and –2.5 standard deviations (SD) of the young adult mean (Baechle & Earle, 2000)


Increased softening of the bone resulting from a gradual decrease in rate of bone formation; a bone mineral density below –2.5 SD of the young adult mean (Baechle & Earle, 2000) (Marieb, 1998)

Outer Vesicles

The terminal ends of the longitudinal tubules of the sarcoplasmic reticulum which store Ca++; also called the outer cisterns and terminal cisternae (Foss and Keteyian, 1998)

Overcoming Muscle Action

            See Concentric Muscle Action (Siff, 2003)


The phenomenon of assistant movers being recruited due to significant increases in loading (Siff, 2003)

Overload Principle

Progressively increasing the volume and/or intensity of exercise during workouts over the course of the training program as fitness capacity improves (Foss and Keteyian, 1998)


Overtraining on a short-term basis where recovery is easily achieved within a few days; often a planned phase of many training programs (Baechle & Earle, 2000)


Imbalance between high volume and/or high intensity training and adequate recovery, resulting in disturbances in physical performance, biologic function, and mood state (Foss and Keteyian, 1998)


Body weight that exceeds the normal or standard weight for a particular individual based on sex, height, and frame size; a BMI of 25.0 to 29.9 (Wilmore & Costill, 2004)

Oxford Method of Training

A strength training method in which exercises are executed in the reverse order; after a warm up, a few repetitions of maximal loads are attempted followed by a progressive shift towards lighter weights with more repetitions (Siff, 2003)


Enzymes that catalyze the transfer of oxygen in oxidation-reduction reactions (Marieb, 1998)


            Process of substances combining with oxygen or the removal of hydrogen (Marieb, 1998)

Oxidation-Reduction (Redox) Reaction

A reaction that couples the oxidation (loss of electrons) of one substance with the reduction (gain of elections) of another substance (Marieb, 1998)

Oxidative Capacity of Muscle

            A measure of the muscle’s maximal capacity to use oxygen (Wilmore & Costill, 2004)

Oxidative Phosphorylation

Process of ATP synthesis during which an inorganic phosphate group is attached to ADP; occurs via the electron transport chain within the mitochondria (Marieb, 1998)

Oxidative State Regulation

A mechanism of control of cellular metabolism that is closely linked to the relative availability of oxygen and subsequent activation of the electron transport system enzyme, cytochrome oxidase (Foss and Keteyian, 1998)

Oxygen Consumption

The amount or rate at which oxygen can be consumed per minute (Foss and Keteyian, 1998)

Oxygen Debt

The volume of oxygen required after exercise to oxidize the lactic acid formed during the exercise (Marieb, 1998)

Oxygen Deficit

The time period during exercise in which the level of oxygen consumption is below that necessary to supply all the ATP required for the exercise; the time period during which an oxygen debt is contracted (Foss and Keteyian, 1998)

Oxygen Diffusion Capacity

            The rate at which oxygen diffuses from one place to another (Wilmore & Costill, 2004)

Oxygen Poisoning (Toxicity)

A condition caused by breathing oxygen under high pressure; symptoms include tingling of fingers and toes, visual disturbances, auditory hallucinations, confusion, muscle and lip twitching, nausea, vertigo, and convulsions (Foss and Keteyian, 1998)

Oxygen Supplementation

The breathing of supplemental oxygen, which is proposed to have ergogenic effects (Wilmore & Costill, 2004)

Oxygen System

An aerobic energy system in which ATP is manufactured when food (principally sugar and fat) is broken down; this system produces ATP most abundantly and is the prime energy source during long-lasting (endurance) activities (Foss and Keteyian, 1998)

Oxygen Transport System (VO2)

Composed of the stroke volume (SV), the heart rate (HR), and the arterial-mixed venous oxygen difference (Foss and Keteyian, 1998)

Oxygen Uptake

A measure of a person’s ability to take in and use oxygen; also known as oxygen consumption (Baechle & Earle, 2000)


            Oxygen-bound form of hemoglobin (Marieb, 1998)


Pain of Effort

Not necessarily a result of injury, but refers to one’s personal interpretation of the intensity of a given effort and is sometimes assessed on a subjective scale called the rating of perceived effort (RPE) (Siff, 2003)

Pain of Injury

A protective response to any activity which is causing or has caused damage to some system of the body (Siff, 2003)


Endocrine gland responsible for the synthesis and secretion of two hormones important to blood glucose regulation; insulin and its beta cells and glucagons from its alpha cells (Foss and Keteyian, 1998)

Parallel Axis Theorem

A theorem stating the relationship between the moment of inertia about an axis through the body’s center of mass (Icm) and any other parallel axis (Iaxis) such that:

(Iaxis = Icm + mr2 ) where m is the mass of the body and r is the perpendicular distance between the axes (Hamill & Knutzen 2003)

Parallel Elastic Component (PEC)

Consists of sarcolemma, rest-state cross bridges, and tissues such as sheaths around the muscle and its sub-units; responsible for the force exerted by a relaxed muscle when it is stretched beyond its resting length (Siff, 2003)

Parallel Processing

A value specified to the generalized motor program that defines the particular expression of the pattern of activity (Schmidt & Lee, 1999)

Parasagittal Planes

            All sagittal planes offset from the midline (Marieb, 1998)

Parasympathetic Nervous System

The division of the autonomic nervous system that oversees digestion, elimination, and glandular function; the resting and digesting subdivision (Marieb, 1998)

Parasympathetic Overtraining Syndrome

A type of overtraining syndrome that includes increased parasympathetic activity at rest and with exercise (Baechle & Earle, 2000)


Parasympathetic Tone

Stat of parasympathetic effects; e.g., unnecessary heart accelerations; normal activity levels of digestive and urinary tracts (Marieb, 1998)

Parathyroid Glands

            Small endocrine glands located on the posterior aspect of the thyroid gland (Marieb, 1998)

Parathyroid Hormone (PTH)

Hormone released by the parathyroid glands that regulates blood calcium level (Marieb, 1998)

Paroxysmal Tachycardia

A sudden onset of rapid heart rate; from paroxysmal meaning sharp or sudden and tachycardia meaning an increased heart rate, usually faster than 100 beats per minute (Foss and Keteyian, 1998)

Parkinson’s Disease

Neurodegenerative disorder of the basal nuclei involving abnormalities of the neurotransmitter dopamine; symptoms include persistent tremor and rigid movement (Marieb, 1998)

Part-Whole Methods

The learning technique in which the task is broken down into its parts for separate practice (Schmidt & Lee, 1999)

Partial Pressure

            The pressure exerted by a single component of a mixture of gases (Marieb, 1998)

Passive (Resting) Recovery

A period following exercise when no cool-down movement or less intense activity is practiced, i.e., the subject remains sedentary during recovery from exercise (Foss and Keteyian, 1998)

Passive Stabilizers

            Ligaments which help to stabilize body segments during a movement (Siff, 2003)

Passive Stretching

            An external load is imposed on relaxed or isometrically contracted muscles (Siff, 2003)

Passive Transport

Membrane transport processes that do not require cellular energy (ATP), e.g., diffusion, which is driven by kinetic energy (Marieb, 1998)


            The physiology of a specific disease or disorder (Wilmore & Costill, 2004)

Peak Bone Mass

            The maximum bone mass achieved (Baechle & Earle, 2000)

Peak Height Velocity

A critical period of pubertal growth in which young athletes may be at increased risk for injury; usually occurs about age 12 in females and age 14 in males; relative weakening of the bone during this stage of growth, muscle imbalances between flexors and extensors around joints, and the relative tightening of the muscle-tendon units spanning rapidly growing bones (Baechle & Earle, 2000)


            Pertaining to the chest (Marieb, 1998)

Pectoral (Shoulder) Girdle

Bones that attach the upper limbs to the axial skeleton; includes the clavicle and the scapula (Marieb, 1998)

Pelvic (Hip) Girdle

Consists of the paired coxal bones that attach the lower limbs to the axial skeleton (Marieb, 1998)


Basin-shaped bony structure composed of the pelvic girdle, sacrum, and coccyx (Marieb, 1998)


A pennate muscle has muscle fibers that align obliquely with the tendon and the angle of the pennation with the tendon can affect the number of sarcomeres per cross-sectional area and thus the maximal force capabilities (Baechle & Earle, 2000)

Peptide Bond

Bond joining the amine group of one amino acid to the acid carboxyl group of a second amino acid with the loss of a water molecule (Marieb, 1998)

Perceptual Anticipation

Anticipation of the arrival of a signal through internal mechanisms or processes (Schmidt & Lee, 1999)

Perceptual Narrowing

The focusing of attention so that specific sources of information are more likely to be received but rare events are more likely to be missed (Schmidt & Lee, 1999)

Perceptual Trace

A construct in Adams’s closed-loop theory; a reference of correctness in memory that has been learned from feedback at the correct target position (Schmidt & Lee, 1999)

Perforating Canals

Canals that run at right angles to the long axis of the bone, connecting the vascular and nerve supplies of the periosteum to those of the central canals and medullary cavity; also called Volkmann’s canals (Marieb, 1998)

Performance Curve

A plot of the average performance of a group of subjects for each of a number of practice trials or blocks of trials (Schmidt & Lee, 1999)

Performance Variable

            An independent variable that affects performance temporarily (Schmidt & Lee, 1999)


            Double-layered serosa enclosing the heart and forming its superficial layer (Marieb, 1998)


Fibrous, connective-tissue membrane covering the external surface of cartilaginous structures (Marieb, 1998)


            Connective tissue enveloping bundles of muscle fibers (Marieb, 1998)


The structured, sequential development of athletic skill or a physiologic capacity brought about by organizing training regimens into blocks of time (macrocycles, mesocycles, etc) (Foss and Keteyian, 1998)


            Double-layered connective tissue that covers and nourishes the bone (Marieb, 1998)

Peripheral Blood Flow

            Blood flow to the extremities and skin (Wilmore & Costill, 2004)

Peripheral Nervous System (PNS)

Portion of the nervous system consisting of nerves and ganglia that lie outside of the brain and spinal cord (Marieb, 1998)

Peripheral Resistance (PR)

A measure of the amount of friction encountered by blood as it flows through the blood vessels (Marieb, 1998)

Peripheral Vascular Disease

Diseases of the systemic arteries and veins, especially those of the extremities that impede adequate blood flow (Wilmore & Costill, 2004)


            That property of membranes that permits passage of molecules and ions (Marieb, 1998)


An unexpected physical event that changes the movement or the movement goal (Schmidt & Lee, 1999)

Pharmacological Agents

            A group of drugs proposed to have ergogenic properties (Wilmore & Costill, 2004)

Phase Transition

            An abrupt shift from one coordination pattern to another (Schmidt & Lee, 1999)


            Dynamic, referring to a dynamic muscle effort or movement (Siff, 2003)

Phasic Tension

Refers to dynamic muscular work in exercises requiring production of a driving force of a given magnitude (Siff, 2003)


The temporal structure of a sequence, usually measured by the ratios of element durations and the overall movement duration (Schmidt & Lee, 1999)

Phosphate Loading

The practice of ingesting sodium phosphate, which has been proposed to have ergogenic properties (Wilmore & Costill, 2004)


            A group of compounds; collectively refers to ATP and PC (Foss and Keteyian, 1998)

Phosphagen System

Provides ATP primarily for short-term, high-intensity activities such as resistance training and sprinting; is active at the start of all exercise regardless of intensity; relies on the chemical reactions of ATP and creatine phosphate as well as the enzymes myosinATPase and creatine kinase (Baechle & Earle, 2000)

Phosphocreatine (PC)

A chemical compound stored in muscle, which when broken down aids in manufacturing ATP (Foss and Keteyian, 1998)

Phosphofructokinase (PFK)

A key rate-limiting enzyme of the anaerobic glycolytic energy system (Wilmore & Costill, 2004)


            Modified lipid, contains phosphorus (Marieb, 1998)


            A key enzyme of the anaerobic glycolytic energy system (Wilmore & Costill, 2004)


The mechanism of ATP synthesis; includes substrate-level and oxidative phosphorylation (Marieb, 1998)

Physical Maturity

            The point at which the body has attained the adult physical form (Wilmore & Costill, 2004)

Physiological Acidosis

            Arterial pH lower than 7.35 resulting from any cause (Marieb, 1998)

Physiological Agents

A group of agents normally present in the body that have been proposed to have ergogenic effects (Wilmore & Costill, 2004)


            Study of the function of living organisms (Marieb, 1998)

Physiological Dead Space

Alveoli that have poor blood flow, poor ventilation, or other problems with the alveolar surface that impair gas exchange (Baechle & Earle, 2000)

Pituitary Gland

Neuroendocrine gland located beneath the brain that serves a variety of functions including regulation of gonads, thyroid, adrenal cortex, lactation, and water balance; the master gland (Marieb, 1998)


An inert substance having the identical physical characteristics of a real drug (Foss and Keteyian, 1998)

Placebo Effect

            The phenomenon of a belief causing real physical change (Baechle & Earle, 2000)


A buildup of lipids, smooth muscle cells, connective tissue, and debris that forms at the site of injury to an artery (Wilmore & Costill, 2004)


The nonliving fluid component of blood within which formed elements and various solutes are suspended  are circulated (Marieb, 1998)

Plasma Cells

            Members of a B cell clone; specialized to produce and release antibodies (Marieb, 1998)

Plasma Membrane

Membrane, composed of three lamina layers, that encloses cell contents; outer limiting cell membrane (Marieb, 1998)


            The shrinking of a cell such as the red blood cell (Foss and Keteyian, 1998)

Plateau Method of Training

A type of training involving the use of a constant load for 3 to 4 sets; this method is commonly used during the early stages of training novices or for transitional active rest phases after weeks of heavy training (Siff, 2003)

Platelet-Derived Growth Factor (PDGF)

A substance released by blood platelets that promotes the migration of smooth muscle cells from the media of an artery into the intima (Wilmore & Costill, 2004)


            Membranes enveloping the lungs and lining the chest walls (Baechle & Earle, 2000)

Pleural Pressure

The pressure in the narrow space between the lung pleura and the chest wall (Baechle & Earle, 2000)


A network of converging and diverging nerve fibers, blood vessels, or lymphatics (Marieb, 1998)


A method of strength and power training that involves an eccentric loading of muscles and tendons followed by a quickly timed concentric contraction; stimulating the muscles by means of a sudden stretch preceding any voluntary effort (Foss and Keteyian, 1998) (Siff, 2003)

Point-To-Point Computation

Models of limb control in which the coordinates of each point in a limb’s trajectory are achieved sequentially by the motor system at the time of response execution (Schmidt & Lee, 1999)

Polar Molecules

            Nonsymmetrical molecules that contain electrically unbalanced atoms (Marieb, 1998)


State of a plasma membrane of an unstimulated neuron or muscle cell in which the inside of the cell is relatively negative in comparison to the outside; the resting state (Marieb, 1998)


            An excessive or abnormal increase in the number of erythrocytes (Marieb, 1998)


A substance of high molecular weight with long, chainlike molecules consisting of many similar (repeated) units (Marieb, 1998)


            A chain of amino acids (Marieb, 1998)

Polypeptide Hormone

Hormones made up of amino acids; growth hormone and insulin are examples (Baechle & Earle, 2000)


The rhythm produced when two effectors simultaneously produce their own, nonharmonic rhythms (e.g., three beats with one finger combined with two beats of another finger) (Schmidt & Lee, 1999)


Literally, many sugars, a pplymer of linked monosaccharides; e.g., starch, glycogen (Marieb, 1998)

Polyunsaturated Fatty Acid

A long chain of carbon atoms bonded to hydrogen atoms, which includes two or more double bonds between carbon atoms in place of hydrogen atoms; tends to lower cholesterol in the body (Foss and Keteyian, 1998), (Baechle & Earle, 2000)

Ponderal Index

            Body height divided by the cube root of body weight (Foss and Keteyian, 1998)

Positive Energy Balance

A condition in which more energy (food) is taken in than is given off; body weight increases as a result (Foss and Keteyian, 1998)

Positive Feedback Mechanisms

Feedback the tends to cause the level of a variable to change in the same direction as an initial change (Marieb, 1998)

Positive/Negative Punishment

The presentation (positive) or removal (negative) of an act, object, or event following a behavior that could decrease the behaviors occurrence; An example of positive punishment would be reprimanding a player after a mistake; An example of negative punishment would be to remove playing time from a player after a mistake.

Positive/Negative Reinforcement

The act of increasing the probability of occurrence of a given behavior by following it with an action, object, or event (positive) or by removing an act, object, or event (negative); An example of positive reinforcement is to award an athlete for success with a trophy; An example of negative reinforcement is to award an athlete for success by removing a difficult conditioning session from practice (Baechle & Earle, 2000)

Positive Transfer

The gain in capability on one task as a result of practice or experience on some other task (Schmidt & Lee, 1999)

Positive Work

Force times distance applied in opposition to the pull of gravity; the work done by a system when the torque exerted by a muscle is greater than the torque of the external load (Foss and Keteyian, 1998) (Hamill & Knutzen 2003)

Post-KR Delay

The interval of time between the presentation of KR and the next movement (Schmidt & Lee, 1999)

Post-Tetanic Potentiation

Any stimulus, whether momentary or not, leaves traces in the nervous system; the after-effect of muscular activity persists for some time following the cessation of the stimulus (Siff, 2003)

Posterior Lobe

The portion of the pituitary gland located closest to the spinal cord (posterior position); also called the neurohypophysis (Foss and Keteyian, 1998)

Postganglionic Neuron

Autonomic motor neuron that has its cell body in a peripheral ganglion and projects its axon to an effector (Marieb, 1998)

Postsynaptic Neuron

            A nerve cell located distal to a synapse (Foss and Keteyian, 1998)


            Stored or inactive energy (Marieb, 1998)


The rate of performing work; the product of force and velocity; the rate of transformation of metabolic potential energy to work or heat (SI unit: watt) (Foss and Keteyian, 1998)

Power Stroke

The tilting of the myosin head, caused by a strong intermolecular attraction between the myosin cross bridge and the myosin head, which causes the actin and myosin filaments to slide across each other (Wilmore & Costill, 2004)


Refers to a period of life before the development of secondary sex characteristics (Baechle & Earle, 2000)

Precision of KR

The level of accuracy with which KR describes the movement outcome produced (Schmidt & Lee, 1999)


The process in which the score on a criterion variable is estimated from one or more predictor variables based on the association between them (Schmidt & Lee, 1999)

Predictor Variable

            The variable(s) from which a criterion variable is predicted (Schmidt & Lee, 1999)

Pre-Exhaustion Training

A method of training involving the performance of a single-joint exercise which preferentially exhausts one of the muscle groups that will be used in the following multi-joint exercise (Siff, 2003)

Preganglionic Neuron

Autonomic motor neuron that has its cell body in the central nervous system and projects its axon to a peripheral ganglion (Marieb, 1998)


            The state of carrying an embryo or fetus in the body (Wilmore & Costill, 2004)


Stretch placed on muscle fibers just prior to contraction (Foss and Keteyian, 1998)

Premature Ventricular Contraction (PVC)

A common cardiac arrhythmia that results in the feeling of skipped or extra beats caused by impulses originating outside the SA node (Wilmore & Costill, 2004)

Premotor Area

            The area of the brain just forward of the primary motor cortex (Foss and Keteyian, 1998)

Premotor Reaction Time

The interval from the stimulus presentation to the initial change in EMG (Schmidt & Lee, 1999)


Reorganization of attention and information processing so that a signal can be received and responded to quickly (Schmidt & Lee, 1999)


The resultant of the interaction of the body’s long-term fitness increase stimulated by training and the opposing short-term fatigue after-effects of training, excluding the effects of any other modifying factors such as exaggerated mental state or illness (Siff, 2003)


            The process of preparing the motor program for initiation (Schmidt & Lee, 1999)

Preselection Effect

In short-term motor memory work, the phenomenon that the memory for subject-selected movements is stronger than for experimenter-selected movements (Schmidt & Lee, 1999)


            Force per unit area (Foss and Keteyian, 1998)


A nerve ending in the wall of the carotid sinus and aortic arch sensitive to vessel stretching (Marieb, 1998)

Pressure Gradient

            Difference in hydrostatic pressure that drives filtration (Marieb, 1998)

Primary Active Transport

A type of active transport in which the energy needed to drive the transport process is provided directly by hydrolysis of ATP (Marieb, 1998)

Primary Amenorrhea

The absence of menarche (the beginning of menstruation) beyond age 18 (Wilmore & Costill, 2004)

Primary Motor Cortex

That area of the brain (cortex) containing groups of motor neurons other than Betz cells (Foss and Keteyian, 1998)

Primary Risk Factors

Risk factors that have been conclusively shown to have a strong association with a certain disease (Wilmore & Costill, 2004)

Prime Mover

Muscle that bears the major responsibility for effecting a particular movement; an agonist (Marieb, 1998)

Principle of Disuse

The theory that a training program must include a maintenance plan to ensure that the gains from training are not lost (Wilmore & Costill, 2004)

Principle of Hard/Easy

The theory that a training program must alternate high-intensity workouts with low-intensity workouts to help the body recover and achieve optimal training adaptation (Wilmore & Costill, 2004)

Principle of Individuality

See Individualization Principle of Training

Principle of Orderly Recruitment

The theory that motor units generally are activated on the basis of a fixed order of recruitment, in which the motor units within a given muscle appear to be ranked according to the size of the motor neuron (Wilmore & Costill, 2004)

Proactive Interference

In the interference theory, a source of forgetting caused by learning imposed before the original learning of some to-be-remembered task (Schmidt & Lee, 1999)

Probe Technique

A secondary-task method that uses reaction time to assess the attention demands of a primary task (Schmidt & Lee, 1999)


            Prominence or projection; series of actions for a specific purpose (Marieb, 1998)


A protein synthesized and secreted by fibroblasts; cleavage of procollagen extensions result in the formation of active/mature collagen molecules (Baechle & Earle, 2000)


            Hormone partly responsible for preparing the uterus for the fertilized ovum (Marieb, 1998)

Progression-Regression Hypothesis

The idea that learning produces a progression to more complex control strategies and that stress or forgetting produces a regression to more simple levels (Schmidt & Lee, 1999)

Progressive Muscle Relaxation (PMR)

A somatopsychic technique by which psychological and physical arousal are self-regulated through the control of skeletal muscle tension’ by going through a series of alternate muscular tensioning and relaxing phases, the athlete learns to become aware of somatic tension and thereby to control it (Baechle & Earle, 2000)

Progressive Overload

Progressively placing greater-than-normal demands on the exercising musculature; the use of progressively greater resistance over a given period, as well as the progressive increase in muscle tension produced by involuntary or voluntary processes (Baechle & Earle, 2000) (Siff, 2003)

Progressive-Resistance Exercise (PRE)

Comprehensive term to cover a wide variety of muscular strength or endurance training practices where progressive overload is emphasized (Foss and Keteyian, 1998)


Inward rotation of the forearm causing the radius to cross diagonally over the ulna – palms face posteriorly (Marieb, 1998)

Proprioceptive Neuromuscular Facilitation (PNF)

A system for promoting the response of neuromuscular mechanisms by stimulating the proprioceptors; a method for improving joint flexibility by contracting against opposition, then relaxing and stretching further (Foss and Keteyian, 1998)


Receptor located in a joint, muscle, or tendon; concerned with locomotion, posture, and muscle tone (Marieb, 1998)


A class of hormones found in nearly all cellular membranes; have a fatty acid as their molecular base; may regulate resting blood flow through vasodilation; numerous other effects suggested (Foss and Keteyian, 1998)


Complex substance containing carbon, oxygen, hydrogen, and nitrogen; composes 10% to 30% of cell mass (Marieb, 1998)

Protein Expression

The end result of multiple sources of control that results in the synthesis of specific structural or enzymatic proteins (Foss and Keteyian, 1998)

Protein Quality

Determined by whether or not a protein supplies amino acids in amounts proportionate to the body’s needs; high-quality or complete proteins supply the required amino acids (Baechle & Earle, 2000)


Carbohydrate-protein molecules; their presence attracts fluid into the cartilage matrix (Baechle & Earle, 2000)


Subatomic particle that bears a positive charge; located in the atomic nucleus (Marieb, 1998)

Proton Acceptor

A substance that takes up hydrogen ions in detectable amounts; commonly referred to as a base (Marieb, 1998)

Proton Donor

            A substance that releases hydrogen ions in detectable amounts; an acid (Marieb, 1998)


            Toward the attached end of a limb or the origin of a structure (Marieb, 1998)

Pseudounipolar Neuron

            Another term for unipolar neuron (Marieb, 1998)


            An instrument used for measuring the relative humidity (Foss and Keteyian, 1998)


Refers to a period of time in which secondary sex characteristics develop and a child is transformed into a young adult (Baechle & Earle, 2000)


            Pertaining to the lungs (Marieb, 1998)

Pulmonary Arteries

            Vessels that deliver blood to the lungs to be oxygenated (Marieb, 1998)

Pulmonary Circuit

System of blood vessels that serves gas exchange in the lungs, i.e., pulmonary arteries, capillaries, and veins (Marieb, 1998)

Pulmonary Diffusion

            The exchange of gases between the lungs and the blood (Wilmore & Costill, 2004)

Pulmonary Valve

Heart valve located between the right ventricle and the pulmonary artery; prevents backflow from the pulmonary arteries into the ventricles during relaxation (diastole) (Baechle & Earle, 2000)

Pulmonary Veins

Vessels that deliver freshly oxygenated blood from the respiratory zones of the lungs to the heart (Marieb, 1998)

Pulmonary Ventilation

            Breathing; consists of inspiration and expiration (Marieb, 1998)


Rhythmic expansion and recoil of arteries resulting from heart contraction; can be felt from outside the body (Marieb, 1998)

Purkinje Fibers

            Modified cardiac muscle fibers of the conduction system of the heart (Marieb, 1998)

Pyramid Method of Training

A training method involving the performance of 4 to 5 sets of an exercise where the load is progressively increased and the number of repetitions decreased with each set (Siff, 2003)

Pyramidal (Corticospinal) Tracts

Major motor pathways concerned with voluntary movement; descend from the frontal lobes of each cerebral hemisphere (Marieb, 1998)


The end product of glycolysis; converted to lactic acid or is transported to the mitochondria (Baechle & Earle, 2000)

Pyruvic Acid

A three-carbon by-product resulting from the metabolism of glucose within the cytoplasm of the cell; enters Krebs Cycle for further breakdown (oxygen available) or is converted to lactic acid (oxygen lacking) (Foss and Keteyian, 1998)

Psychological Refractoriness

            The delay in the response to the second of two closely spaced stimuli (Schmidt & Lee, 1999)


Q10 Effect

An increase in the speed of cellular metabolic reactions as a result of an increase in body temperature; the 10 is from culture studies indicating that reaction speeds double with a 10º C increase in temperature (Foss and Keteyian, 1998)


            Very slow concentric or eccentric movement occurring at near-maximal loads (Siff, 2003)


Describes rapid movement involving little resistance or muscular effort; the ability of the central nervous system to contract, relax, or control muscle function without involvement of any preliminary stretch; high speed movement which does not encounter large external resistance or require great strength, power, or energy consumption (Siff, 2003)



The transfer of heat between two objects through electromagnetic waves (Foss and Keteyian, 1998)

Radius of Gyration

A measure of the distribution of a body’s mass about an axis of rotation (Hamill & Knutzen 2003)


            Branch of a nerve, artery, vein, or bone (Marieb, 1998)

Random Practice

A practice sequence in which the tasks being practiced are ordered (quasi-) randomly across trials; high contextual interference (Schmidt & Lee, 1999)

Rate Coding

            The rate at which the motor units are fired (Baechle & Earle, 2000)

Rate of Force Development (RFD)

A measurement of how much force is developed in a specific amount of time; a measurement of explosive strength (Siff, 2003)

Rate of Perceived Exertion (RPE)

Developed by Borg to enable one to estimate the intensity of cardiovascular exer4cise on a scale running originally from 6 to 22; the range was chosen because the average adult pulse rate varies from approximately 60 at rest to a maximum of 220 beats per minute (Siff, 2003)

Rate-Limiting Enzymes

A few enzymes that serve as “gate-keepers” – i.e., they control the rate at which glycolytic and mitochondrial metabolic reactions are allowed to proceed (Foss and Keteyian, 1998)

Rate-Limiting Step

            The slowest reaction in a series of reactions (Baechle & Earle, 2000)

Rate-Pressure Product

The product of heart rate and systolic blood pressure, which provides a noninvasive estimate of myocardial oxygen consumption (Foss and Keteyian, 1998)

Reach/Grasp Action

An action that coordinates the limb-transport component with the opening and closing of the grasp component (Schmidt & Lee, 1999)


            A substance taking part in a chemical reaction (Marieb, 1998)

Reaction Time

            The time interval between stimulus and response (or initiation of movement) (Siff, 2003)

Reactive Ability

The switch from stretching to active contraction using the elastic energy of the stretch to increase the power of the subsequent contraction, a process that is central to the so-called stretch-shortening cycle and plyometric action (Siff, 2003)

Reactivity Coefficient

The explosive strength index relative to body weight or the weight of the object being moved (Siff, 2003)

Recall Schema

A construct in schema theory; the relationship between past parameters, past initial conditions, and the movement outcomes produced by these combinations (Schmidt & Lee, 1999)


A cell or nerve ending of a sensory neuron specialized to respond to particular types of stimuli; molecule that binds specifically with other molecules, e.g., neurotransmitters, hormones, antigens (Marieb, 1998)

Receptor Anticipation

Anticipation of the arrival of a stimulus due to sensory information about its time of arrival (Schmidt & Lee, 1999)

Receptor Inhibition

Basic reflex that causes antagonist muscle group to relax while agonist group is undergoing concentric contraction (Foss and Keteyian, 1998)

Receptor Potential

            A graded potential that occurs at a sensory receptor membrane (Marieb, 1998)

Reciprocal Inhibition

A relaxed body will promote a relaxed mind; a positive side effect of the reduced muscle tension may be an increase in smooth, fluid, or efficient movement as well as an increased range of motion around the joint (Baechle & Earle, 2000)

Recognition Schema

A construct in schema theory; the relationship between past initial conditions, past movement outcomes, and the sensory consequences produced by these combinations (Schmidt & Lee, 1999)


Increasing the pressure exerted on the body, usually in a recompression chamber, to cause nitrogen bubbles to go back into solution (Wilmore & Costill, 2004)

Recovery Oxygen

Net amount of oxygen consumed during recovery from exercise; oxygen consumed in excess of the amount consumed at rest over the same time period (reported in liters ) (Foss and Keteyian, 1998)


A means of varying muscular force output; increases in force output are achieved by recruiting additional motor units (Baechle & Earle, 2000)


            In a chemical reaction, the state of having an added hydrogen (Baechle & Earle, 2000)


Chemical reaction in which electrons and energy are gained by a molecule (often accompanied by gain of hydrogen ions) or oxygen is lost (Marieb, 1998)


            Autonomic reaction to stimuli (Marieb, 1998)

Reflex-Reversal Phenomenon

The phenomenon by which a given stimulus can produce two different reflexive responses depending on the function of the limb in a movement (Schmidt & Lee, 1999)

Refractory Period

Period during which an excitable cell is not responsive to a threshold stimulus (Marieb, 1998)


            Replacement of destroyed tissue with the same kind of tissue (Marieb, 1998)

Regression Line

The line of best fit between two variables, whose slope and intercept are determined by regression analysis (Schmidt & Lee, 1999)

Relative Body Fat

            The ratio of fat mass to total body mass, expressed as a percentage (Wilmore & Costill, 2004)

Relative Force

An invariant feature of the motor program that defines the relationships between the forces produced in the various actions in a movement (Schmidt & Lee, 1999)

Relative Frequency of Knowledge of Results

The percentage of trials for which knowledge of results is provided; the absolute frequency divided by the number of trials (Schmidt & Lee, 1999)

Relative Humidity

Raito of water vapor in the atmosphere to the amount of water vapor required to saturate the atmosphere at the same temperature (Foss and Keteyian, 1998)

Relative Phase

A measure of temporal coordination that expresses the position of one limb within its cycle relative to the other limb within its cycle (Schmidt & Lee, 1999)

Relative Refractory Period

Follows the absolute refractory period; interval when a threshold stimulus is unable to trigger an action potential (Marieb, 1998)

Relative Retention

Measures of retention in which the performance on the retention test is evaluated in relation to the level of performance reached in original learning (Schmidt & Lee, 1999)



Relative Weight

The percentage by which an individual is either overweight or underweight, generally determined by dividing the person’s weight by the mean weight for the medium frame category for his or her height (from standard weight tables) (Wilmore & Costill, 2004)

Releasing Factor

A group of specific substances produced by the hypothalamus that can stimulate or inhibit the release of all hormones produced by the adenohypophysis with the exception of the endorphins (Foss and Keteyian, 1998)


            The aspect of measurement related to the repeatability of a score (Schmidt & Lee, 1999)

Relief Interval

In an interval-training program, the time between work intervals as well as between sets (Foss and Keteyian, 1998)

Remote Angular Momentum

The angular momentum of a segment about the total body center of mass (Hamill & Knutzen 2003)

Remoteness Effect

In intertrial correlation matrices, the tendency for trials that are progressively more separated in the practice sequence to correlate systematically lower with each other (Schmidt & Lee, 1999)


An enzyme formed by the kidneys to convert a plasma protein called angiotensinogen into angiotensin II

Renin-Angiotensin Mechanism

The mechanism involved in renal control of blood pressure; the kidneys responds to decreased blood pressure or blood flow by forming renin, which converts angiotensinogen into angiotensin I, which is finally converted into angiotensin II; angiotensin II constricts arterioles and triggers aldosterone release (Wilmore & Costill, 2004)

Rep-Pausing Sets

A training method which entails taking a short rest break during the execution of a set to facilitate recovery, diminish the pain of effort, or overcome any loss of motivation before competing the remaining repetitions (Siff, 2003)

Repetitions (Reps)

In an interval-training program; the number of work intervals within one set (Foss and Keteyian, 1998)

Repetition Maximum (RM)

The maximal load that a muscle group can lift over a given number of repetitions before fatiguing; for example, a 10RM load is the maximal load that can be lifted over ten repetitions (Foss and Keteyian, 1998)

Repetition Principle

Consistent repetition diminishes spurious neuromuscular activity and enables one to concentrate predominantly on the task being learned; expertise is established and the movement becomes automatic only after further and consistent repetitions (Siff, 2003)

Repetition To Failure Method

A training method that involves continuing the exercise until it is impossible to execute another repetition without assistance; often used for muscle endurance and definition training (Siff, 2003)

Repetitive Effort Method

This training method consists of repetitively lifting a weight whose magnitude is increased as muscular strength grows (Siff, 2003)


            Movement of the membrane potential to the initial resting (polarized)state (Marieb, 1998)

Residual Volume (RV)

            Volume of air remaining the lungs at end of maximal expiration (Foss and Keteyian, 1998)

Resistance Arm

            See Moment Arm (Hamill & Knutzen 2003)

Resistance Exercise

High-intensity exercise in which the muscles are pitted against high resistance or immovable forces and, as a result, muscle cells increase in size (Marieb, 1998)

Resistance Force

Force generated by a source external to the body (e.g., gravity, inertia, friction) that acts contrary to muscle force; a force that resists the effort force in a lever (Baechle & Earle, 2000) (Hamill & Knutzen 2003)


The process involved in supplying the body with oxygen and disposing of carbon dioxide (Marieb, 1998)

Respiratory Alkalosis

A condition in which increased carbon dioxide clearance allows blood pH to increase (Wilmore & Costill, 2004)

Respiratory Exchange Ratio (RER)

The ratio of the amount of carbon dioxide produced by the body to the amount of oxygen consumed (Foss and Keteyian, 1998)

Respiratory Center

Composed of several widely dispersed groups of neurons located bilaterally in the lower portion of the brain stem (the pons and medulla oblongata) (Baechle & Earle, 2000)

Respiratory System

Organ system that carries out gas exchange; includes the nose, pharynx, larynx, trachea, bronchi, and lungs (Marieb, 1998)

Respondent Conditioning

            A type of conditioning in which the response is modified by a preceding stimulus (Siff, 2003)

Response-Chaining Hypothesis

A movement-control theory whereby each element in a sequence is triggered by movement feedback from the previous element (Schmidt & Lee, 1999)         

Response Phase

            The time interval between the appearance of the EMG signal and the motor action (Siff, 2003)

Response-Programming Stage

A stage of information processing in which the previously chosen response is transformed into overt muscular action (Schmidt & Lee, 1999)

Response-Selection Stage

A stage of information processing in which the response associated with the presented stimulus is selected (Schmidt & Lee, 1999)

Response Time

            See Response Phase


            Resting during recovery from exercise (Foss and Keteyian, 1998)


In an interval-training program, a type of relief interval involving moderate moving about, such as walking and flexing of arms and legs (Foss and Keteyian, 1998)

Resting Membrane Potential (RMP)

The voltage that exists across the plasma membrane during the resting state of an excitable cell; ranges from –50 to –200 millivolts depending on cell type (Marieb, 1998)

Resting Metabolic Rate (RMR)

The body’s metabolic rate early in the morning following an overnight fast and eight hours of sleep (Wilmore & Costill, 2004)


The use of natural and artificial means of recovery following training and competition (Siff, 2003)

Retention Interval

            The interval between the end of original learning and the retention test (Schmidt & Lee, 1999)

Retention Test

A performance test administered after a retention interval for the purpose of assessing learning (Schmidt & Lee, 1999)

Reticular Formation

Functional system that spans the brain stem; involved in regulating sensory input to the cerebral cortex, cortical arousal, and control of motor behavior (Marieb, 1998)

Reticular Lamina

A layer of extracellular material containing a fine network of collagen protein fibers; together with the basal lamina it is a major component of the basement membrane (Marieb, 1998)


            Immature erythrocyte (Marieb, 1998)


            Recovery of conditioning after a period of inactivity (Wilmore & Costill, 2004)

Retroactive Interference

In the interference theory, a source of forgetting caused by practice imposed between the original learning and the retention test for a to-be-remembered task (Schmidt & Lee, 1999)

Reversal Hypothesis

A view of the relationship between arousal and performance that is based on individual differences in the interpretation of one’s arousal level (Schmidt & Lee, 1999)


A five-carbon sugar molecule that when linked to adenine forms adenosine, the molecular foundation for ATP, ADP, and AMP (Foss and Keteyian, 1998)

Ribosomal RNA (rRNA)

A constituent of ribosome; exists within the ribosomes of cytoplasm and assist in protein synthesis (Marieb, 1998)


            Cytoplasmic organelles at which proteins are synthesized (Marieb, 1998)

Right Bundle Branch

Part of the conduction system of the heart that receives the impulse from the AV bundle and passes it along to the Purkinje Fibers (Baechle & Earle, 2000)

Risk Factor

A condition, trait, or habit that is associated with an increased risk or danger of developing a specific health problem in the future (Foss and Keteyian, 1998)

RNA (Ribonucleic Acid)

Nucleic acid that contains ribose and the bases A, G,C, and U; carries out DNA’s instructions for protein synthesis (Marieb, 1998)

Root-Mean-Square Error (RMSE)

The square root of the average squared deviations of a set of values from a target value; typically used as a measure of tracking proficiency (Schmidt & Lee, 1999)


            The turning of a bone around its own long axis (Marieb, 1998)

Rotational Kinetic Energy

The capacity to do angular work; the product of half the moment of inertia and the angular velocity squared (Hamill & Knutzen 2003)

Rotational Work

            The product of torque times angular displacement (Baechle & Earle, 2000)       

Rule of Sixty Percent

The training volume of any stage (day or microcycle) with light loading should be approximately 60% of the volume of a stage with heavy (maximal or near-maximal) loading (Siff, 2003)


S-Factors of Fitness

Strength, speed, stamina, suppleness (flexibility), skill (neuromuscular efficiency), style, structure (somatotype, size, shape), and spirit (Siff, 2003)

Sacral Vertebrae

5 vertebrae of the lower back; fused together and make up the rear part of the pelvis (Baechle & Earle, 2000)

Sagittal Plane

A longitudinal (vertical) plane that divides the body or any of its parts into right and left portions (Marieb, 1998)


            A 0.9% salt solution that is isotonic to the blood (Foss and Keteyian, 1998)

Saltatory Conduction

The propagation of a nerve impulse form one node of Ranvier to another along a myelinated fiber (Foss and Keteyian, 1998)


            The plasma membrane surface of a muscle fiber (Marieb, 1998)


            The smallest contractile unit of muscle; extends from one Z disc to the next (Marieb, 1998)

Sarcomere Hypertrophy

An increase in the size and number of the sarcomeres which comprise the myofibrils; these may be added in series or parallel with the existing myofibrils, although only the parallel growth with contribute to an increased ability to produce muscle tension (Siff, 2003)


Aging associated muscle wasting that results in lower basal metabolic rate, weakness, reduced activity levels, decreased bone density, and lowered caloric needs (Foss and Keteyian, 1998)


            Muscle protoplasm (Foss and Keteyian, 1998)

Sarcoplasmic Hyperplasia

            Involves an increase in the number of sarcoplasmic organelles (Siff, 2003)

Sarcoplasmic Hypertrophy

The volume of non-contractile protein and semifluid plasma between the muscle fibers increases; although the cross-sectional area of the muscle increases, the density of muscle fibers per unit area decreases and there is no corresponding increase in muscle strength (Siff, 2003)

Sarcoplasmic Reticulum (SR)

            Specialized endoplasmic reticulum of muscle cells (Marieb, 1998)

Saturated Fatty Acids

A fatty acid where all carbon atoms of the chain structure are filled with hydrogen atoms (i.e., there is no double bonding); often found in animal fats, eggs, and dairy products; tends to raise cholesterol in the body (Foss and Keteyian, 1998), (Baechle & Earle, 2000)

Savings Score

A statistic used in transfer experiments, representing the “savings’ in practice time resulting from experience on some other task (Schmidt & Lee, 1999)


A graph on which subjects’ scores on two tests are jointly represented as data points (Schmidt & Lee, 1999)


The basis for schema theory; a rule, concept, or relationship formed on the basis of experience (Schmidt & Lee, 1999)

Second-Class Lever

A lever for which the muscle force and resistive force act on the same side of the fulcrum, with the muscle force acting through a moment arm longer than that through which the resistive force acts, as when the calf muscles work to raise the body onto the balls of the feet; due to its mechanical advantage (i.e., its long moment arm) the required muscle force is smaller than the resistive force (body weight); a lever in which the resistance force acts between the fulcrum and the effort force (Baechle & Earle, 2000) (Hamill & Knutzen 2003)

Second Messenger

Intracellular molecule generated by the binding of a chemical (hormone or neurotransmitter) to a plasma membrane receptor; mediates intracellular responses to the chemical messenger (Marieb, 1998)

Second Wind

A phenomenon characterized by a sudden transition from an ill-defined feeling of distress or fatigue during the early portion of prolonged exercise to a more comfortable, less stressful feeling later in the exercise (Foss and Keteyian, 1998)

Secondary Amenorrhea

The cessation of menstruation in a woman with previously normal menstrual function (Wilmore & Costill, 2004)


Secondary-Task Method

A collection of experimental methods whereby learning on a main task can be estimated by use of simultaneous secondary measures of performance (Schmidt & Lee, 1999)

Segmental Method

A method of calculating the total body center of mass of a multi-segment body by summing the product of the locations of the centers of mass of the segments and the mass of the respective segment and dividing by the total body mass (Hamill & Knutzen 2003)

Selective Attention

The ability to inhibit awareness of some stimuli in order to process others; suppression of task-irrelevant cues in order to process the task-relevant cues in the limited attentional space (Baechle & Earle, 2000)

Selectively Permeable Membrane

A membrane that allows certain substances to pass while restricting the movement of others; also called differentially permeable membrane (Marieb, 1998)


Perceived self-confidence about a given task in a specific situation; it is the sense of success that an athlete feels he or she embodies or can control; someone of high self-efficacy does not doubt his or her ability to succeed at a given task, even when failure is experienced (Baechle & Earle, 2000)


From dynamic pattern theory; a view that describes motor control as emerging from the interaction of the components of the movement system (Schmidt & Lee, 1999)

Semilunar Valves

            Valves that prevent blood return to the ventricles after contraction (Marieb, 1998)

Semipermeable Membrane

A membrane permeable to some but not all particles or substances (Foss and Keteyian, 1998)


That aspect of measurement dealing with the possibility of detecting changes in a dependent measure in relation to varying experimental conditions (Schmidt & Lee, 1999)

Sensory (Afferent) Nerves

Nerves that contain processes of sensory neurons and carry impulses to the central nervous system (Marieb, 1998)

Sensory Areas

Functional areas of the cerebral cortex that provide for conscious awareness of sensation (Marieb, 1998)

Sensory Receptor

Dendritic end organs, or parts of other cell types, specialized to respond to a stimulus (Marieb, 1998)


An invariant feature of motor programs in which the order of elements is fixed (Schmidt & Lee, 1999)

Serial Processing

A style of information processing in which stages of processing are arranged sequentially in time (Schmidt & Lee, 1999)



Serial Tasks

Movements in which a series of discrete elements are combined, with the order of elements being important (Schmidt & Lee, 1999)

Series Elastic Component (SEC)

Includes the tendon, the cross-bridges, myofilaments, titin filaments and the Z-discs; stores elastic energy when put under tension by the force developed in actively contracted muscle (Siff, 2003)


            An excitatory neurotransmitter chemical (Foss and Keteyian, 1998)

Sesamoid Bones

Short bones embedded in tendons, variable in size and number, many of which influence the action of muscles; largest is the patella (kneecap) (Marieb, 1998)


In an interval training program, a group of work and relief intervals (Foss and Keteyian, 1998)


A rapid, involuntary cycle of contraction and relaxation of skeletal muscles that generates heat (Wilmore & Costill, 2004)

Shock Training

            See Plyometrics (Siff, 2003)

Short-Term Memory

A memory store with a capacity of about seven elements, capable of holding moderately abstract information for up to 30 seconds; analogous to consciousness; a “work space” for processing (Schmidt & Lee, 1999)

Short-Term Sensory Store

A functionally limitless memory store for holding literal information for about 1 second (Schmidt & Lee, 1999)

Shtanga Functional Pressure Test

A test used to ascertain if an athlete is overtrained; requires the athlete to breathe in relaxed fashion for a few minutes, then inhaling maximally and holding the breath for 15 to 20 seconds before stopping the nose and exhaling as forcibly as possible for 2 seconds; blood pressure is measured before the test and immediate afterwards and after 2 minutes of relaxed breathing; changes in blood pressure are analyzed (Siff, 2003)


A construct in most theories of transfer, indicating the extent to which certain aspects of two tasks are the same (Schmidt & Lee, 1999)

Simon Effect

A type of stimulus-response compatibility effect in which irrelevant directional or locational information interferes with the action (Schmidt & Lee, 1999)

Simple Reaction Time

Reaction time from a task in which a single known response is produced when a single stimulus is presented (Schmidt & Lee, 1999)

Simplification Hypothesis

The idea that the factor structure of a skill becomes progressively simpler with practice (Schmidt & Lee, 1999)


A training device in which certain features of a task are duplicated, allowing for practice that resembles the transfer task (Schmidt & Lee, 1999)

Single-Channel Hypothesis

A theory of attention suggesting that the system can process only a single stimulus leading to a response at any given time (Schmidt & Lee, 1999)

Sinoatrial (SA) Node

Specialized myocardial cells in the wall of the right atrium, pacemaker of the heart (Marieb, 1998)

Size Principle

Recruitment of motor units within muscle on the basis of the size of their motorneurons; small ones recruited first, then intermediate, then large ones (Foss and Keteyian, 1998)

Skeletal Cartilage

Comprises most of the skeleton in early fetal life; articular cartilage, nasal cartilage in the adult skeleton (Marieb, 1998)

Skeletal Muscle

Muscle composed of cylindrical multinucleate cells with obvious striations; the muscles attached to the body’s skeleton; voluntary muscle (Marieb, 1998)

Skeletal System

System of protection and support composed primarily of bone and cartilage (Marieb, 1998)


Movements that are dependent on practice and experience for their execution, as opposed to being genetically defined (Schmidt & Lee, 1999)

Skinfold Fat Thickness

The most widely applied field technique used to estimate body density, relative body fat, and fat-free mass; it involves measurement with calipers of the skinfold fat at one or more sites (Wilmore & Costill, 2004)

Sliding Filament Theory

A proposed mechanism for muscle action where shortening and elongation are the result of actin protein filaments sliding inward and outward over myosin protein filaments (Foss and Keteyian, 1998)

Slope (b)

            One of the constants of a linear equation; the inclination of the line (Schmidt & Lee, 1999)

Slow Component (Of Recovery)

The slow decline in oxygen consumption during recovery (reported in liters) lasting up to 60 minutes or more; follows the initial fast component; formerly lactacid oxygen debt (Foss and Keteyian, 1998)

Slow Glycolysis

If oxygen is present in sufficient quantities in the mitochondria, the end product of glycolysis (pyruvate) enters the mitochondria and is converted to acetyl CoA prior to entering into the Krebs Cycle (Baechle & Earle, 2000)

Slow Twitch (ST) Fiber

A muscle fiber characterized by slow contraction time, low anaerobic capacity, and high aerobic capacity, all making the fiber suited for low-power output activities; also known as Type I fiber (Foss and Keteyian, 1998)

Smooth Muscle

Spindle-shaped cells with one centrally located nucleus and no externally visible striations (bands); found mainly in the walls of hollow organs (Marieb, 1998)

Sodium-Potassium (Na+ - K+) Pump

A primary active transport system that simultaneously drives Na+ out of the cell against a steep gradient and pumps K+ back in (Marieb, 1998)


            The substance that is dissolved in a solution (Marieb, 1998)

Solute Pump

Enzyme-like protein carrier that mediates active transport of solutes such as amino acids and ions uphill against their concentration gradients (Marieb, 1998)


            The cell body of a neuron (Foss and Keteyian, 1998)


            Pertaining to the body (Foss and Keteyian, 1998)

Somatic Anxiety

            Physical symptoms of stress such as tense muscles and tachycardia (Baechle & Earle, 2000)

Somatic Nervous System

Division of the peripheral nervous system that provides the motor innervation of skeletal muscles; also called the voluntary nervous system (Marieb, 1998)

Somatic Reflexes

            Reflexes that activate skeletal muscle (Marieb, 1998)


A class of substances produced by the liver and several other tissues as a result of growth hormone influence; composed of amino acid chains; stimulate the growth of muscle and cartilage by turning on phases of protein synthesis (Foss and Keteyian, 1998)


A substance produced by the hypothalamus that on release can inhibit the secretion of growth hormone from the adenohypophysis; also called growth hormone release inhibiting hormone (GHRIH) (Foss and Keteyian, 1998)

Somatosensory System

The part of the sensory system dealing with reception in the body wall and limbs, receives inputs from exteroceptors, proprioceptors, and interoceptors (Marieb, 1998)


            The body type or physical classification of the human body (Foss and Keteyian, 1998)

Spacing Effect

In memory experiments, repetitions of the criterion task that are increasingly separated in time are remembered more effectively (Schmidt & Lee, 1999)

Spatial Anticipation

The anticipation of which stimulus (or the response to it) will occur; also called event anticipation (Schmidt & Lee, 1999)

Spatial Discrimination

            The ability of neurons to identify the site or pattern of stimulation (Marieb, 1998)

Spatial Summation

An increase in responsiveness of a nerve resulting from the additive effect of numerous nearby stimuli (Foss and Keteyian, 1998)

Spatial-Temporal Goal

A subgoal for the performer in which a pattern of limb movement defined in terms of both space and time is selected; the major product of running a motor program (Schmidt & Lee, 1999)

Specific Gravity

            The ratio of the density of an object to the density of water (Foss and Keteyian, 1998)

Specific Heat

The heat required to change the temperature of a unit mass of a substance by one degree (Foss and Keteyian, 1998)

Specificity of Individual Differences

Henry’s theory of the structure of motor abilities, according to which motor tasks are thought to be composed of many independent abilities (Schmidt & Lee, 1999)

Specificity of Learning

The concept that the similarity of the environmental conditions and processing in practice, compared to those in transfer, has a strong influence on transfer performance (Schmidt & Lee, 1999)

Specificity Principle

Principle underlying construction of a training program for a specific activity or skill and the primary energy systems involved during performance (Foss and Keteyian, 1998)

Speed-Accuracy Trade Off

The general principle describing a person’s tendency to decrease the accuracy of a movement when the speed of it is increased (Schmidt & Lee, 1999)

Speed Strength

A quality where speed development against resistance is vital, but strength acquisition is somewhat less important; synonymous with power (Siff, 2003)

Spinal Cord

The bundle of nervous tissue that runs from the brain to the first to third lumbar vertebrae and provides a conduction pathway to and from the brain (Marieb, 1998)

Spinal Nerves

            The 31 nerve pairs that arise from the spinal cord (Marieb, 1998)


A device used to collect, store, and measure either inspired or expired gas volume (Foss and Keteyian, 1998)

Split Routine

A training system involving the division of a routine into two distinct components, each of which trains a different body zone in successive workouts (Siff, 2003)

Spongy Bone

            Internal layer of skeletal bone; also called cancellous bone (Marieb, 1998)

Sport Psychology

The subdiscipline of exercise science that seeks to understand the influence of behavioral processes on skilled movement; the three major goals of sport psychology are to measure psychological phenomena, investigate the relationships between psychological variables and performance; and to apply theoretical knowledge to improve athletic performance (Baechle & Earle, 2000)

Sports Medicine

Umbrella term that refers to all aspects of sport and exercise science, especially as used in the U.S.; examples are Kinesiology, cardiac rehabilitation, adult fitness, and athletic medicine (Foss and Keteyian, 1998)


            Ligaments reinforcing a joint are stretch or torn (Marieb, 1998)


            Resistance to a disturbance in the body’s equilibrium (Hamill & Knutzen 2003)


Muscles stabilizing or supporting a body segment statically or dynamically while other muscles carry out a movement involving other joints (Siff, 2003)

Stable Equilibrium

The state of a body in which the body will return to its original location if it is displaced (Hamill & Knutzen 2003)

Staggered Sets

A training routine in which supersets alternate one set for major muscle groups with a set for minor muscles in an attempt to gainfully use the long rest intervals between each set of exercises for the major muscles (Siff, 2003)

Starting Strength

The ability of the muscles to develop force at the beginning of the working contraction before external movement occurs (Siff, 2003)

State Anxiety

A temporary state of worry or concern about a particular situation or activity (Schmidt & Lee, 1999)

Static Dynamic Methods

A method of developing muscular strength involving the sequential combination in one exercise of isometric and dynamic (auxotonic) muscular activity, each of which can provide its own distinct quantitative characteristics (Siff, 2003)

Static Equilibrium

            Sense of head position in space with respect to gravity (Marieb, 1998)

Static Flexibility

The range of motion about a joint; usually measured with a goniometer or flexometer as the arc in degrees at the end when there is no joint motion (Foss and Keteyian, 1998)

Static Stabilization

The muscles either contract isometrically or quasi-isometrically to stabilize a body segment during a movement (Siff, 2003)

Static Stretching

Refers to flexibility exercises which use the weight of the body or its limbs to load the soft tissues; includes free static stretching and passive static stretching (Siff, 2003)


The branch of mechanics in which the system being studied undergoes no acceleration (Hamill & Knutzen 2003)

Steady State

Pertaining to the time period during which a physiological function (such as VO2) remains at a constant (steady) state (Foss and Keteyian, 1998)


Step Method

A training method where the number of repetitions remains fixed while the load is increased after each set until the prescribed number of repetitions can no longer be maintained (Siff, 2003)


Group of chemical substances including certain hormones and cholesterol; they are fat soluble and contain little oxygen (Marieb, 1998)


A characteristic of muscles and springs defined as the change in tension divided by the change in length (Schmidt & Lee, 1999)


            An excitant or irritant; a change in the environment that evokes a response (Marieb, 1998)

Stimulus-Identification Stage

A stage of information processing in which the stimulus is identified, and features or patterns are abstracted; often divided into separate encoding and identification stages (Schmidt & Lee, 1999)

Stimulus Onset Asynchrony (SOA)

The interval of time between the onsets of two stimuli, as in the double-stimulation paradigm (Schmidt & Lee, 1999)

Stimulus-Response Compatibility

The degree to which the set of stimuli and associated responses are “naturally” related to each other (Schmidt & Lee, 1999)

Stimulus-Response Viewpoint

A tradition in psychology and motor behavior stressing the responses produced as a function of stimuli presented, without regard to the intervening mental events or processes (Schmidt & Lee, 1999)

Storage Problem

A problem with early notions of motor programming in which the number of necessary programs was so large that their storage in the central nervous system seemed impossible (Schmidt & Lee, 1999)


            Standard temperature, pressure, dry (Foss and Keteyian, 1998)


The maximal force or torque a muscle or muscle group can generate at a specific or determined velocity (Foss and Keteyian, 1998)

Strength Deficit

The difference between maximum strength (voluntary effort) produced in a given action and absolute strength (involuntary effort) of which the athlete is capable in that same action (Siff, 2003)

Strength Endurance

The ability to effectively maintain muscular function under work conditions of long duration (Siff, 2003)

Strength Speed

A quality in which speed development is vital, but strength is more important; synonymous with power (Siff, 2003)


            Any disruption form homeostasis or mental and physical calm (Baechle & Earle, 2000)

Stress Fracture

            Microfractures in bone due to structural fatigue (Baechle & Earle, 2000)


Any stimulus that directly or indirectly causes the hypothalamus to initiate stress reducing responses, such as the fight or flight response (Marieb, 1998)

Stretch Reflex

Contraction of muscles to produce movement or tension due to muscle spindle stretch via a sharp tap on tendon or pull of gravity on skeleton (Foss and Keteyian, 1998)

Stripping Method

A method of training which involves working progressively with an increasing load and a decreasing number of repetitions in a pyramid fashion until a target load is reached with about 3 to 4 repetitions, where a partner then removes 5 to 10 kg and the athlete exercises to failure, followed by another 5 to 10 kg being removed and athlete once again exercising to failure; used for muscle endurance and definition training (Siff, 2003)


Interference with the blood supply to the brain causing necrosis; due to embolus, thrombus, or burst vessel; due to cerebral artery atherosclerosis or aneurysm (Foss and Keteyian, 1998)

Stroke Volume (SV)

            Amount of blood pumped out of a ventricle during one contraction (Marieb, 1998)

Structural Exercise

Exercise which involve force vectors through the spine and hip and allowing for greater absolute loads to be used in training (Baechle & Earle, 2000)

Structural Interference

Interference among tasks caused by the simultaneous use of the same receptors, effectors, or processing systems (Schmidt & Lee, 1999)

Structural (Fibrous) Proteins

Consist of extended, strandlike polypeptide chains forming a strong, ropelike structure that is linear, insoluble in water, and very stable; e.g., collagen (Marieb, 1998)

Subjective Reinforcement

A construct in Adams’s closed-loop theory; term used to describe the subject’s self-generated error signal, based on comparing feedback against a reference or correctness (Schmidt & Lee, 1999)

Submaximal Endurance Capacity

The average absolute power output a person can maintain during affixed period of time on a cycle ergometer, or the average speed or velocity a person can maintain during a fixed period of time (Wilmore & Costill, 2004)

Submaximal Exercise

            All intensities of exercise below maximal exercise intensity (Wilmore & Costill, 2004)


            A reactant on which an enzyme acts to cause a chemical action to proceed (Marieb, 1998)

Successive Approximations

            Short-term goals that progressively increase in difficulty (Baechle & Earle, 2000)

Succinate Dehydrogenase (SDH)

            A key enzyme of the oxidative enzyme intensity (Wilmore & Costill, 2004)


            Pertaining to activation of the sweat glands (Foss and Keteyian, 1998)

Summary Knowledge of Results

Augmented information about a set of performance trials presented after the set is completed (Schmidt & Lee, 1999)


Accumulation of effects, especially those of muscular, sensory, or mental stimuli (Marieb, 1998)

Super Sets

A set that consists of two separate exercises in which the athlete performs set 1 of exercise 1, moves immediately to set 1 of exercise 2, then performs set 2 of exercise 1, set 2 of exercise 2 and so on until the chosen number of sets is completed (Siff, 2003)


A condition in which the body over-adapts in anticipation of repeated exposure to the same stressor (Siff, 2003)


            Located close to or on the body surface (Marieb, 1998)

Superior Vena Cava

            Vein that returns blood from body regions superior to the diaphragm (Marieb, 1998)


            The outward rotation of the forearm causing palms to face anteriorly (Marieb, 1998)

Supplemental Motor Area (SMA)

Medial portion of cortical area 6, which is called the sports skills area; sends axons to directly innervate distal motor units (Foss and Keteyian, 1998)

Suppressor T Cells

            Regulatory T lymphocytes that suppress the immune response (Marieb, 1998)

Supramaximal Methods

Methods of training with loads beyond the maximum amount an athlete can successfully complete intended to increase strength involving forced reps (reps with help from a partner), restricted range reps (smaller range of motion), cheating (use of momentum), and ballistics (dropping a weight rapidly to recruit the stretch reflex) (Siff, 2003)

Surface Drag

A form of fluid resistance that results from the friction of a fluid passing along the surface of an object (Baechle & Earle, 2000)


An immovable fibrous joint; with one exception, all bones of the skull are united by sutures (Marieb, 1998)

Sympathetic Nervous System

The division of the autonomic nervous system that activates the body to cope with some stressor (danger, excitement, etc); the fight, fright, and flight subdivision (Marieb, 1998)

Sympathetic Overtraining Syndrome

A type of overtraining syndrome that includes increased sympathetic activity at rest (Baechle & Earle, 2000)

Sympathetic (Vasomotor) Tone

State of partial vasoconstriction of the blood vessels maintained by sympathetic fibers (Marieb, 1998)


            A joint in which the bones are connected by fibrocartilage (Marieb, 1998)


Functional junction or point of close contact between two neurons or between a neuron and an effector cell (Marieb, 1998)

Synaptic Cleft

            Fluid-filled space at a synapse (Marieb, 1998)

Synaptic Delay

            Time required for an impulse to cross a synapse between two neurons (Marieb, 1998)

Synaptic Knobs (Boutons)

            The bulbous distal endings of the telodendria (Marieb, 1998)

Synaptic Vesicles

            Small membranous sacs containing the neurotransmitter acetylcholine (Marieb, 1998)


            Immovable joint (Marieb, 1998)

            A joint in which the bones are united by hyaline cartilage (Marieb, 1998)


A joint in which the bones are united by a ligament or a sheet of fibrous tissue (Marieb, 1998)


Muscle that aids the action of a prime mover by effecting the same movement or by stabilizing joints across which the prime mover acts to prevent undesirable movements (neutralizer) (Marieb, 1998)


            A completely ossified joint; a fused joint (Marieb, 1998)

Synovial Fluid

Fluid secreted by the synovial membrane; lubricates joint surfaces and nourishes articular cartilages (Marieb, 1998)

Synovial Joint

            Freely moveable joint exhibiting a joint cavity; also called diarthrosis (Marieb, 1998)

Synthesis (Combination) Reaction

A chemical reaction in which larger, more complex atoms or molecules are formed from simpler ones (Marieb, 1998)

Systematic Desensitization (SD)

A hybrid of cognitive and somatic techniques that allow an athlete to replace a fear response to various cues with a relaxation response; based upon counterconditioning (Baechle & Earle, 2000)


            Pertaining to the whole body (Marieb, 1998)

Systemic Circuit

            System of blood vessels that serves gas exchange in the body tissues (Marieb, 1998)


            Period when either the ventricles or the atria are contracting (Marieb, 1998)

Systolic Pressure

Pressure exerted by blood on the blood vessel walls during ventricular contractions (Marieb, 1998)

T Cells

Lymphocytes that mediate cellular immunity; include helper, killer, suppressor, and memory cells; also called T lymphocytes (Marieb, 1998)

T Tubule (Transverse Tubule)

Extension of the muscle cell plasma membrane (sarcolemma) that protrudes deeply into the muscle cell (Marieb, 1998)


            A heart rate over 100 beats per minute (Marieb, 1998)


The concept of decreasing training duration by 80 to 90% some five days to three weeks before athletic competition, which may or may not be accompanied by an associated increase in training intensity (Foss and Keteyian, 1998)

Target Cell

A cell that is capable of responding to a hormone because it bears receptors to which the hormone can bind (Marieb, 1998)

Target Heart Rate (THR)

            A predetermined heart rate to be obtained during exercise (Foss and Keteyian, 1998)

Task Analysis

A process of determining the underlying abilities and structure of a task or occupation (Schmidt & Lee, 1999)

Tau (t)

A view of time-to-contact information based on the rate of expansion of the approaching object on the retina of the eye (Schmidt & Lee, 1999)


            A system of classification (Schmidt & Lee, 1999)


            The terminal branches of an axon (Marieb, 1998)

Tempo Changing Set

A type of training involving the changing of the tempo (or pace) of an exercise during each set, so that either one repetition may be performed faster or slower than other repetitions, or the duration of the concentric, isometric, and eccentric phases of as ingle repetition may be changed relative to one another during each repetition (Siff, 2003)

Temporal Anticipation

The anticipation of when a given stimulus will arrive or when a movement is to be made (Schmidt & Lee, 1999)

Temporal Summation

An increase in responsiveness of a nerve, resulting from the additive effect of frequently occurring stimuli (Foss and Keteyian, 1998)

Temporal Variability

            The inconsistency of some event with respect to time (Schmidt & Lee, 1999)


            Cord of dense fibrous tissue attaching muscle to bone (Marieb, 1998)


            Inflammation of tendon sheaths, typically caused by overuse (Marieb, 1998)



Force applied to a structure that does not move; in muscle, the static or isometric tension developed with the recycling of ATP at cross-bridge sites (Foss and Keteyian, 1998)

Teratogenic Effects

            Effects that cause abnormal fetal development (Wilmore & Costill, 2004)

Terminal Feedback

            Feedback given after the movement’s completion (Schmidt & Lee, 1999)


Male sex hormone produced by the testes; during puberty promotes virilization, and is necessary for normal sperm production (Marieb, 1998)


A smooth, sustained muscle contraction resulting from high-frequency stimulation; an infectious disease caused by an anaerobic bacterium (Marieb, 1998)


Subcortical portion of the brain that, along with the basal ganglia, provides an information loop back to the premotor cortex to assist in the selection and initiation of chosen movements (Foss and Keteyian, 1998)

Thermal Stress

            Stress imposed on the body by external temperature (Wilmore & Costill, 2004)

Thermic Effect of Activity

The energy expended in excess of the resting metabolic rate to accomplish a given task or activity (Wilmore & Costill, 2004)

Thermic Effect of a Meal

The energy expended in excess of resting metabolic rate associated with digestion, absorption, transport, metabolism, and storage of ingested food (Wilmore & Costill, 2004)


            The science of the transformation of heat and energy (Foss and Keteyian, 1998)


            Heat production (Marieb, 1998)


            Receptor sensitive to temperature changes (Marieb, 1998)

Third-Class Lever

A lever for which the muscle force and resistive force act on the same side of the fulcrum, with the muscle force acting through a moment arm shorter than that through which the resistive force acts; the mechanical advantage is thus less than 1.0, so the muscle force has to be greater than the resistive force to produce torque equal to that produced by the resistive force; a lever in which the effort force acts between the fulcrum and the line of action of the resistance force (Baechle & Earle, 2000) (Hamill & Knutzen 2003)

Thoracic Vertebrae

            12 vertebrae in the middle to upper back (Baechle & Earle, 2000)


            The portion of the body trunk above the diaphragm and below the neck (Marieb, 1998)

Threshold Stimulus

            Weakest stimulus capable of producing a response in an irritable tissue (Marieb, 1998)


            Enzyme that induces clotting by converting fibrinogen to fibrin (Marieb, 1998)


            Platelets; cell fragments that participate in blood coagulation (Marieb, 1998)


            A clot that develops and persists in an unbroken blood vessel (Marieb, 1998)

Thyroid Gland

            Endocrine gland active in immune response (Marieb, 1998)

Thyroid Hormone (TH)

The major hormone secreted by thyroid follicles; stimulates enzymes concerned with glucose oxidation (Marieb, 1998)

Thyroid-Stimulating Hormone (TSH)

            Andenohypophyseal hormone that regulates secretion of thyroid hormones (Marieb, 1998)

Thyrotropin (TSH)

A hormone secreted by the anterior lobe of the pituitary gland that promotes the release of thyroid hormones (Wilmore & Costill, 2004)

Thyroxine (T4)

Iodine-containing hormone secreted by the thyroid gland; accelerates cellular metabolic rate in most body tissues (Marieb, 1998)

Tidal Volume

            Volume of air inspired or expired per breath (Foss and Keteyian, 1998)

Tight Junction

            Area where plasma membranes of adjacent cells are fused (Marieb, 1998)

Time-To-Contact (Tc)

            Information about the time remaining until a moving object arrives at the eye (Schmidt & Lee, 1999)


            A group of similar cells and their intercellular substance specialized to perform a specific function; primary tissue types of the body are epithelial, connective, muscle, and nervous tissue (Marieb, 1998)

Tissue Perfusion

            Blood flow through body tissues or organs (Marieb, 1998)


            A large-molecular weight protein that interconnects the Z-disks to the myosin filaments via the M-bands in myofibrils; responsible for much of the resting tension in highly stretched fibers and plays an important role in located the thick filaments in the center of the sarcomere; helps comprise the series and parallel elastic components of muscle tissue (Siff, 2003)


            Postural or anti-gravity, referring to muscles that offer stability, aid posture, and resist gravity (Siff, 2003)


            A measure of the ability of a solution to cause a change in cell shape or tone by promoting osmotic flows of water (Marieb, 1998)


            The effectiveness of a force to overcome the rotational inertia of an object; the product of force and the perpendicular distance from the line of action of the force to the axis of rotation (SI unit; Newton-meter); the product of the magnitude of a force and the perpendicular distance from the line of action of the force to the axis of rotation (Foss and Keteyian, 1998) (Hamill & Knutzen 2003)

Total Lung Capacity (TLC)

            Volume of air in the lungs at the end of maximal inspiration (Foss and Keteyian, 1998)

Total Peripheral Resistance

            The resistance of the entire systemic circulation (Baechle & Earle, 2000)

Total Variability (E)

            The standard deviation of a set of scores about a target value; a measure of overall accuracy (Schmidt & Lee, 1999)


            Any of the fibrous bands extending from the capsule into the interior of an organ; struts or thin plates of bone in spongy bone (Marieb, 1998)

Trabecular Bone

            Spongy bone (Baechle & Earle, 2000)

Trace-Decay Theory

            A theory holding that forgetting is caused by the spontaneous “decay” or weakening of memory over time (Schmidt & Lee, 1999)


            Windpipe; cartilage-reinforced tube extending from the larynx to bronchi (Marieb, 1998)


            A collection of nerve fibers in the CNS having the same origin, termination, and function (Marieb, 1998)


            Refers to the potential to develop strength in response to a specific training regime and depends largely on genetic factors and pre-training status (Siff, 2003)


            An exercise program to develop an individual for a particular event; increasing skill of performance and energy capacities are of equal consideration (Foss and Keteyian, 1998)

Training Age

            The length of time the child has been resistance training (Baechle & Earle, 2000)


Training Duration

            The length of the training program (Foss and Keteyian, 1998)

Training Effect

            Temporary or extended changes in body structure or function caused by repeated bouts of exercise (Foss and Keteyian, 1998)

Training Frequency

            The number of times per week for the training workout (Foss and Keteyian, 1998)

Trait Anxiety

            A personality variable or disposition relating to the probability that one will perceive an environment as threatening; acts as a primer for the athlete to experience (state) anxiety (Baechle & Earle, 2000)

Transfer-Appropriate Processing

            The concept that practice should be arranged so that the processing capability learned is appropriate for some goal criterion task or conditions (Schmidt & Lee, 1999)

Transfer Design

            An experimental design for measuring learning effects, in which all treatment groups are transferred to a common level of the independent variable (Schmidt & Lee, 1999)

Transverse (Horizontal) Plane

            A plane running from right to left, dividing the body into superior and inferior parts (Marieb, 1998)


            The pattern of a T-tubule spaced between and perpendicular to two sarcoplasmic reticulum vesicles (Baechle & Earle, 2000)

Trials-Delay Technique

            A procedure in which the presentation of knowledge of results for a movement is delayed, during which the learner practices one or more other movements (Schmidt & Lee, 1999)

Tricuspid Valve

            The right atrioventricular valve (Marieb, 1998)

Triggered Reaction

            A coordinated response to an environmental stimulus whose latency is shorter than reaction time yet longer than the long-loop reflex (Schmidt & Lee, 1999)


            Fats and oils composed of fatty acids and glycerol; are the body’s most concentrated source of energy fuel; also known as neutral fats (Marieb, 1998)   

Triiodothyronine (T3)

            Secretion and function similar to those of thyroxine (Marieb, 1998)


            A combination of three amino acids united by means of a peptide bond (Marieb, 1998)


            Pertaining to nutrition or nourishment (Foss and Keteyian, 1998)

Tropic Hormone

            A hormone that regulates the function of another endocrine organ (Marieb, 1998)


A protein involved in muscular contraction; runs along the length of the actin filament in the groove of the double helix (Baechle & Earle, 2000), (Foss and Keteyian, 1998)


A protein involved in muscular contraction; situated at regular intervals along the actin filament and has a high affinity for calcium ions (Baechle & Earle, 2000), (Foss and Keteyian, 1998)


            An abnormal growth of cells; a swelling; cancerous at times (Marieb, 1998)


A brief period of contraction followed by relaxation in the response of a motor unit to a stimulus (nerve impulse) (Foss and Keteyian, 1998)

Two-Factor Model of Training

A training process involving the superimposition of two-after-effects following the application of a training load: long-term fitness after-effect and short-term fatigue after-effect (Siff, 2003)

Type I Collagen

The major collagen of bone, tendon, and ligaments consists of this protein (Baechle & Earle, 2000)

Type II Collagen

            Collagen present in cartilage (Baechle & Earle, 2000)

Type I Muscle Fiber

Commonly used classification for muscle fibers that display characteristics of slow twitch, nonfatigue, and mostly oxidative metabolism (Foss and Keteyian, 1998)

Type IIA Muscle Fiber

Commonly used classification for muscle fibers that display characteristics of fast twitch, medium fatigue, and combined oxidative and glycolytic metabolism (Foss and Keteyian, 1998)

Type IIB Muscle Fiber

Commonly used classification for muscle fibers that display characteristics of fast twitch, rapid fatigue, and mostly glycolytic metabolism (Foss and Keteyian, 1998)

Type IIC Muscle Fiber

Commonly used classification for muscle fibers that display characteristics of fast twitch but cannot be further classified; predominant early fetal type but very few present after maturity (Foss and Keteyian, 1998)


Uniaxial Joint

            Joints that allow rotation in only one axis; example is the elbow (Baechle & Earle, 2000)

Unit of Action

A “piece” of behavior that can be utilized repeatedly in various actions, producing essentially the same movements (but scaled to the environment) each time (Schmidt & Lee, 1999)

Unmyelinated Fibers

Axons lacking a myelin sheath and therefore conducting impulses quite slowly (Marieb, 1998)

Unsaturated Fatty Acids

A fatty acid where all the carbon atoms of the chain structure are not filled with hydrogen atoms (i.e., there is double bonding); found mostly in vegetable oils (Foss and Keteyian, 1998)

Unstable Equilibrium

The state of a body in which the body continues to increase its displacement if it is displaced (Hamill & Knutzen 2003)

Upper Body (Android) Obesity

Obesity that follows the typically male pattern of fat storage, in which fat is stored primarily in the upper body, particularly in the abdomen (Wilmore & Costill, 2004)


Increased target cell formation of receptors in response to increasingly higher levels of the hormones to which they respond (Marieb, 1998)



That aspect of measurement related to the extent to which a test measures what the experimenter wanted it to measure (Schmidt & Lee, 1999)


Valsalva Maneuver

            Making an expiratory effort with the glottis closed (Foss and Keteyian, 1998)

Valvular Heart Disease

            A disease involving one or more of the heart valves (Wilmore & Costill, 2004)

Variability in Practice

A prediction of schema theory; transfer is predicted to be facilitated when goals are systematically varied from trial to trail during practice (Schmidt & Lee, 1999)

Variable Error (VE)

The standard deviation of a set of scores about the subject’s own average score; a measure of movement consistency (Schmidt & Lee, 1999)

Variable Error in Timing (Vet)

The within-subject standard deviation of the duration of some process or event (Schmidt & Lee, 1999)


            Pertaining to blood vessels or richly supplied with blood vessels (Marieb, 1998)

Vascular Spasm

            Immediate response to blood vessel injury; results in constriction (Marieb, 1998)


            Narrowing of blood vessels (Marieb, 1998)


            Relaxation of the smooth muscles of the blood vessels producing dilation (Marieb, 1998)


Intermittent contraction or relaxation of the precapillary sphincter beds resulting in a staggered blood flow when tissue needs are not extreme (Marieb, 1998)

Vasomotor Center

            Brain area concerned with regulation of blood vessel resistance (Marieb, 1998)

Vasomotor Fibers

Sympathetic nerve fibers that regulate the contraction of smooth muscle in the walls of blood vessels, thereby regulating blood vessel diameter (Marieb, 1998)


            People who eat no animal products (Foss and Keteyian, 1998)


            Blood vessels that return blood toward the heart from the circulation (Marieb, 1998)


            A decrease in the diameter of a vein (Foss and Keteyian, 1998)

Venous Return

Amount of blood returned to the heart via the systemic venous system (Foss and Keteyian, 1998)

Ventilatory Breakpoint

The point at which ventilation increases disproportionately compared with oxygen consumption (Wilmore & Costill, 2004)

Ventilatory Efficiency

The amount of ventilation required per liter of oxygen consumed (Foss and Keteyian, 1998)

Ventilatory Equivalent

            The ratio of minute ventilation to oxygen uptake (Baechle & Earle, 2000)



            Pertaining to the front; anterior (Marieb, 1998)


Paired, inferiorly located heart chambers that function as the major blood pumps; cavities in the brain (Marieb, 1998)

Ventricular Fibrillation

A serious cardiac arrhythmia in which the contraction of the ventricular tissue is uncoordinated, affecting the heart’s ability to pump blood (Wilmore & Costill, 2004)

Ventricular Tachycardia

A serious cardiac arrhythmia consisting of three or more consecutive premature ventricular contractions (Wilmore & Costill, 2004)


            A small vein (Marieb, 1998)

Verbal Pretraining

The presentation of stimulus or display elements of the task in isolation so that they can be more easily responded to later in whole-task performance (Schmidt & Lee, 1999)

Vertebral Column (Spine)

Formed of a number of individual bones called vertebrae and two composite bones (sacrum and coccyx) (Marieb, 1998)

Very Low Density Lipoprotein (VLDL)

            A lipoprotein carrier of cholesterol (Wilmore & Costill, 2004)


            A small, liquid-filled sac or bladder (Marieb, 1998)

Vestibular Apparatus

The receptors in the inner ear that are sensitive to the orientation of the head with respect to gravity, to rotation of the head, and to balance (Schmidt & Lee, 1999)


Short periods of low-frequency mechanical vibration (10-35 Hz) may induce faster recovery, have a positive effect on different body systems, modulate muscle activity, elicit a higher stable state of strength and power, lower arterial pressure, and enhance oxidative processes; powerful whole-body vibration (26 Hz) through the lower extremities produces increases in jumping power (Siff, 2003)


            Pertaining to an internal organ of the body or the inner part of a structure (Marieb, 1998)

Visceral Muscle

Type of smooth muscle; its cells contract as a unit and rhythmically, are electrically coupled by gap junctions, and often exhibit spontaneous action potentials (Marieb, 1998)


            State of being sticky or thick (Marieb, 1998)

Visual Proprioception

Gibson’s concept that vision can serve as a strong basis for perception of the movements and positions of the body in space (Schmidt & Lee, 1999)

Vital Capacity (VC)

The volume of air that can be expelled from the lungs by forcible expiration after the deepest inspiration; total exchangeable air (Marieb, 1998)


Vital Signs

Includes pulse, blood pressure, respiratory rate, and body temperature measurements (Marieb, 1998)


            Organic compounds required by the body in minute amounts (Marieb, 1998)

Voluntary Muscle

            Muscle under control of will; skeletal muscle (Marieb, 1998)

Voluntary Nervous System

            The somatic nervous system (Marieb, 1998)


Wallerian Degeneration

A process of disintegration of an axon that occurs when it is crushed or severed and cannot receive nutrients form the cell body (Marieb, 1998)

Warm-Up Decrement

            The decrement in performance occurring after a rest period (Schmidt & Lee, 1999)

Water-Soluble Vitamins

A category of vitamins that are water soluble and consequently are not stored in the body and must be constantly supplied in the diet; examples are vitamin C and B-complex vitamins (Foss and Keteyian, 1998)


            A unit of power (Foss and Keteyian, 1998)

Wave Summation

Increase in force due to an additive effect caused by rapid stimulation of a single motor unit (Foss and Keteyian, 1998)

WBGT (Web Bulb Globe Temperature) Index

An index calculated from dry bulb, wet bulb, and black bulb temperatures; indicates the combined severity of environmental heat conditions (Foss and Keteyian, 1998)


The force exerted by gravity on an object (SI unit: Newton, traditional unit: kilogram of weight) (Foss and Keteyian, 1998)

Weight Bearing

Having the additional stress of one’s body weight involved in exercise (Baechle & Earle, 2000)

Wet Bulb Thermometer

An ordinary thermometer with a wetted wick wrapped around the bulb; the wet bulb’s temperature is related to the amount of moisture in the air; when the wet bulb and dry bulb temperatures are equal, the air is completely saturated with water and the relative humidity is 100%

Wet Muscle

            Muscle that has not been desiccated (Baechle & Earle, 2000)

White Matter

            White substance of the central nervous system; myelinated nerve fibers (Marieb, 1998)

Wineglass Effect

A slip of an object through the fingertips that triggers an increased grip force within 30 milliseconds or so (Schmidt & Lee, 1999)



Force expressed through a displacement but with no limitation on time (SI unit: joule) (Foss and Keteyian, 1998)

Work-Energy Theorem

The relationship between work and energy stating that the work done is equal to the change in energy (Hamill & Knutzen 2003)

Work Interval

That portion of an interval-training program consisting of the work effort (Foss and Keteyian, 1998)


In an interval-training program, a type of relief interval involving light or mild exercise

such as rapid walking or jogging (Foss and Keteyian, 1998)


Work-Relief Ratio

In an interval-training program, a ratio relating the duration of the work interval to the duration of the relief interval (Foss and Keteyian, 1998)


Yielding Muscle Action

            See Eccentric Muscle Action



Z Line

A protein band that defines the distance of one sarcomere in the myofibril (Foss and Keteyian, 1998)

Zinovieff Method

            See Oxford Method of Training

Zone Training

Refers to training a specific body zone in a particular workout session so that an entire body training regime using this method must be spread over several sessions or days; split routines constitute one variation of this method (Siff, 2003)

Zones of Optimal Functioning

A modification of the inverted-U principle to include individual, task, and environmental differences (Schmidt & Lee, 1999)





Baechle, T. R., & Earle, R.W. (2000). Essentials of Strength and Conditioning (2nd ed.). Champaign: Human Kinetics.

Foss, M. & Keteyian, S. (1998). Physiological Basis for Exercise and Sport.(6th ed.). Boston: Mcgraw-Hill .

Hamill, J. & Knutzen, K.M. (2003). Biomechanical Basis of Human Movement (2nd ed.). Baltimore: Lippincott Williams & Wilkins.

Marieb, E. (1998).  Human Anatomy and Physiology(4th ed.). Menlo Park: Addison Wesley Longman.

Schmidt, R.A. & Lee, T.D. (1999). Motor Control and Learning: A Behavioral Emphasis (3rd ed.). Champaign: Human Kinetics.

Siff, M.C. (2003). Supertraining (6th ed.). Denver: Supertraining Institute.

Wilmore, J.H. & Costill, D.L. (2004). Physiology of Sport and Exercise (3rd Ed.) Champaign: Human Kinetics.


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