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

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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.

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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.

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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

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Blood pressure

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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

Vasculature efficiency Increase in blood plasma

• Increases blood volume • Decreases blood viscosity – Blood flows more easily – Enhances delivery of O2 to the muscles • Particularly in the arteries • More efficient vasodilation & vasoconstriction – – Improves redistribution of blood Better at shunting to active muscles