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Effects of Exercise. Responses to Exercise. . There Are Two Kinds of Response to Exercise . Immediate, short-term responses that last only for the duration of the exercise itself and the recovery period.
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Effects of Exercise Responses to Exercise.
There Are Two Kinds of Response to Exercise • Immediate, short-term responses that last only for the duration of the exercise itself and the recovery period. • Chronic responses, which are long-term adaptations to exercise bouts. We call the summation of the chronic adaptations the training effect.
Acute Cardiovascular Responses to Exercise • Effects on cardiac output (Q). At rest, cardiac output is 4 to 6 litres per minute; That is. 70 beats per minute x 8- ml per beat. = 5.6 litres per minute. Cardiac output increases linearly with in the intensity of exercise up to exhaustion.
Effects on Stroke Volume • Stoke volume increases, because more blood is returning to the heart (venous return), for exercise levels up to 40-60% of a persons maximum capacity. • Therefore maximal stroke volume occurs during sub maximal work.
Increases in Heart Rate • The heart rate increases as exercise intensity increases, up to maximum heart rate values. This is called tachycardia. • Note remember your maximum heart rate is approximately 220 – your age.
Effects of Systolic Blood Pressure • Systolic blood pressure increases linearly with increasing exercise intensity, because of increased cardiac output. • For example, at rest systolic blood pressure is 120mmHg whilst during exercise it may reach 180mmHg.
Effects on Blood Plasma Volume • The blood plasma volume usually decreases during strenuous exercise, especially in hot weather, because of increased sweating. • In turn this leads to the loss from the body of water and electrolytes.
Effects on Blood Acidity • Blood acidity increases, because of increased amounts of lactic acid circulating the body
Effects on the Muscle Glycogen Content • There is a decrease in muscle glycogen content during strenuous exercise, as glycogen is being used as a primary energy source.
Effects on Coronary Blood Flow • Coronary blood flow increases about fivefold during strenuous exercise, in order to supply oxygen to meet the increased demands of the cardiac muscle.
Effects on Blood Flow • Blood flow to the working muscles and skin increases because of: • Increased cardiac output. • Greater distribution of blood away from non-working areas to active muscles.
Effects on Blood Flow • Therefore: • 80-85% Q goes to the working muscles, because of the relaxation of precapillary sphincters. • Blood flow to the kidneys and the abdomen decreases, because of the contraction of the precapillary sphincters. • Blood flow to the lungs increases as the right ventricle increases its activity during exercise.
Effects on the Arteriovenous Oxygen Difference (a-VO2 diff.) • When the body is at rest, the arterial oxygen concentration is 19ml per 100 ml, while the venous oxygen concentration is 13ml per 100 ml. • Therefore 6ml per 100ml of oxygen is being used by the working muscles. That is: a-VO2 diff = 6. • During strenuous exercise, the venous oxygen concentration can drop to 2ml per 100ml. That is: a-VO2 diff = 17ml.
Task most important part of the lesson Fill in table on training effects of vascular system. Fill in table on training effects upon the athletes heart,
Effects on Ventilation • Ventilation increases from 6 litres per minute at rest to more than 100 litres per minute during exercise. This is achieved by increases in; • Respiration rate: from 15 to 40-50 breaths per minute. • Tidal volume: from 10% of vital capacity to more than 50% of vital capacity.
Effects on Lung Diffusion • During strenuous exercise there is a threefold increase in oxygen diffusion from the alveoli to the blood.
Effects on Oxygen Uptake or Volume of Oxygen Consumed (VO2) • Oxygen uptake (VO2) is the amount of oxygen taken up and used by the body. It reflects the total amount of work being done by the body. • During strenuous exercise there can be a twenty-fold increase in VO2 which increases linearly with increases in the intensity of the exercise.
Effects on Oxygen Uptake or Volume of Oxygen Consumed (VO2) • As a person approaches exhaustion, his or her VO2 will reach a maximum above which it will not increase further. • This figure is his or her VO2 Maximum; that is, the largest amount of oxygen that a person can utilize within a given time (for example, 50 litres per minute).