Presentation on theme: "Effects of Exercise Responses to Exercise.. There Are Two Kinds of Response to Exercise Immediate, short-term responses that last only for the duration."— Presentation transcript:
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,
Acute Respiratory Adaptations to Exercise
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 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).