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physical fitness

capacity of the heart, blood vessels, lungs, and muscles to function at a high level of efficiency

range of motion ROM

total motion possible in a joint, described by the terms related to body movements, ability to flex, extend, abduct or adduct etc

lean body mass

structural and functional elements in cells, body water, muscle, bones, and other body organs - basically EVERYTHING THAT ISN'T FAT

body fat

adipose tissue, primary role is to store energy for later use. Classified into essential body fat and storage body fat

adenosine triphosphate ATP

immediately usable for of chemical energy needed for all cellular function, including muscular contraction

adenosine Diphosphate ADP

a substance involved in energy metabolism formed by the breakdown of adenosine triphosphate

creatine phosphate CP

a unique high energy molecule stored in muscles, is tapped to regenerate ATP while the metabolic pathways are adjusting to the suddenly higher demands for ATP


a metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP

lactic acid

Produced in muscle cells from the reduction of pyruvate (under anaerobic conditions) to regenerate NAD+ so that glycolysis can continue. A rise in lactic acid usually accompanies an increase in physical activity.


End product of fermentation in muscle cells, humans use lactic acid fermentation to generate ATP when oxygen is scarce


Powerhouse of the cell, organelle that is the site of ATP (energy) production

exercise specificity

exercise training principle explaining that specific exercise demands made on the body produce specific responses by the body

central nervous system CNS

the brain and spinal cord

motor unit

conduct impulses from the CNS to the periphery signaling muscles to contract or to relax

sliding filament theory

muscular contraction occurs when the cross-bridges extending from the myosin myofilaments attach to the actin myofilaments and pull them past the myosin myofilaments

valsalva maneuver

when the breath is held, the glottis in the back of the throat is closed. exerting force with the glottis closed results in an increase in pressure within the chest cavity (intrathoracic pressure). this increase in pressure squeezes down on the large veins in the chest cavity, impeding venous return. resulting in less flow of blood and oxygen to the brain, dizziness and fainting may occur


result of an increase in the size of individual muscle cells due to proliferation of actin and myosin myofilaments with in the myofibrils especially within the fast twitch muscle fibers

reversibility principle

training adaptations will gradually decline if not reinforced by a maintenance program. strength training even once per week is sufficent to maintain strength gains and muscle size


muscle wasting

delayed onset muscle soreness DOMS

occurs 24-48 hours after strenuous exercise may be caused by microscopic damage to muscle cell ultrastructure to to excessive mechanical force exerted by the muscle and connective tissue

stretch reflexes

A reflex contraction of a muscle in response to stretching of an attached tendon or of the muscle itself.

muscle spindle

the sensory organ within a muscle that is sensitive to stretch and thus protects the muscle against to much stretch

golgi tendon organ

a sensory organ within a tendon that when stimulated causes an inhibition of the entire muscle group to protect against to much force


a protein molecule in red blood cells specifically adapted to carry oxygen molecules

heart rate

the number of heart beats per minute

stroke volume

the amount (quantity) of blood pumped per heart beat

cardiac output

the amount of blood pumped from the heart per minute

steady state

the term that describes the point at which the energy needs of the body during exercise are being met aerobically

anaerobic threshold AT

the point at which exercise intensity can no longer met the metabolic demands of the muscles aerobically and the muscles have to rely on anaerobic metabolism for ATP


the principle that a physiological system subjected to above-normal stress will respond by increasing in strength or function accordingly

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