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Long term responses of exercise on the cardiovascular system.
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Long term responses of exercise on the cardiovascular system Cardiovascular system: cardiac hypertrophy; increase in stroke volume; increase in cardiac output, decrease in resting heart rate; capillarisation; increase in blood volume; reduction in resting blood pressure; decreased recovery time; increased aerobic fitness
The Grades • Look at the different descriptions below, and research as far as you feel you need to: • If you want to get a Pass, simply • Describe what happens to the cardiovascular system when we start to exercise, and after 6 weeks of training. • If you want to get a Merit, • Extend your description to include an explanation of how the cardiovascular system responds when we start to exercise and after 6 weeks of training. • You will need to provide some examples from sport in general and football in particular here.
Cardiac Hypertrophy • Increase in the size of the heart • Increase in thickness of the myocardium • Allows left ventricle to fill more completely during diastole • Larger ventricular wall • Can contract more forcefully • Pumps more blood into the systemic system • More efficient heart Endurance athletes have larger ventricle cavities and Anaerobic athletes have thicker ventricle walls.
Stroke Volume • Due to Cardiac hypertrophy, this increases both at rest and during exercise. • Greatest amongst endurance athletes • Increased size of ventricular cavity • Up to 140ml per beat • Improved contractility of the myocardium • In trained athlete at rest: • EDV 130, ESV 40, SV 90 • In untrained athlete at rest • EDV 130, ESV 60, SV 70
Heart Rate • Resting heart rate untrained – 80bpm • Resting heart rate athlete – 60bpm • Resting elite endurance athlete – 35bpm • Bradycardia • When h.r. falls below 60bpm • Due to a slowing of the rate of the S.A. node • Lance Armstrong 35bpm • Steve Redgrave 45bpm • Cardiac output • At rest – Same for athlete & non athlete • Therefore, athlete has increased stroke volume • During exercise much larger for trained athlete
Blood pressure Capillarisation • Of trained muscles • New capillaries may develop • Existing capillaries become more efficient. • Brings about more efficient delivery of blood to working muscles • More O2 reaches the muscles • Decreases, particularly at rest • Mainly from endurance training • Blood pressure at a maximal or sub-maximal level remains unchanged
Vasculature efficiency Increase in blood plasma • Particularly in the arteries • More efficient vasodilation & vasoconstriction • Improves redistribution of blood • Better at shunting to active muscles • Increases blood volume • Decreases blood viscosity • Blood flows more easily • Enhances delivery of O2 to the muscles