Month: August 2020
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Action potential
Reversal of polarity or change in electrical potential. A brief change in the electrical potential of an axon that is the physical basis of the nervous system impulse. Temporary change in electrical potential which occurs between the inside and the outside of a nerve or muscle fibre when a nerve impulse is sent. Change in…
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Acclimatization
The adaptive changes that occur when an individual undergoes prolonged or repeated exposure to a stressful environment; these changes reduce the physiological strain produced by such an environment. The biological process whereby an organism adapts to a new environment. This adaptation actually occurs on a molecular level. One example is when natural microorganisms adapt so…
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Absolute submaximal workload
A set exercise load performed at any intensity from just above resting to just below maximum.
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Working heart rate
Heart rate taken at the completion of the aerobic portion of the workout to determine if the individual was in his target zone and at proper intensity for age and physical fitness level.
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Warm-up
A balanced combination of static stretch and rhythmic limbering exercises that prepare the body for more vigorous exercise. The first phase of any exercise prescription. Warm-up is the first part of the three-segment workout. It prepares the body physically and mentally for the conditioning bout. The 5-10 minutes of low-intensity movement at the beginning of…
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Vital capacity
The greatest volume of air that can be forcibly exhaled after the deepest inspiration. The greatest amount of air that can be exhaled following a maximal inhalation. The largest amount of air which a person can exhale at one time. Maximal amount of gas that can be exhaled after a maximal inspiration. Maximum amount of…
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Ventricle
The two large pumping chambers of the heart. The right ventricle pumps blood to the lungs, whereas the left ventricle, which has a muscle wall three times thicker than that of the right ventricle, pumps blood to all parts of the body. Cavities or chambers in the body, generally filled with fluid. In the brain,…
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Vasodialation
Dilation of blood vessels due to the relaxation of smooth muscles.
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Vasonconstriction
Narrowing of blood vessels as a result of smooth muscle contraction.
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Vaisalva maneuver
A dangerous condition that can occur if an individual holds his breath, causing the glottis to close and stomach muscle to contract, forming an unequal pressure in the chest cavity, reduced blood flow to the heart, and insufficient oxygen supply to the brain. Dizziness, temporary loss of consciousness may occur.