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 Capillarisation • Of trained muscles Blood pressure • Decreases, particularly at rest – Mainly from endurance training • Blood pressure at a maximal or sub-maximal level remains unchanged – 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 • Particularly in the arteries • More efficient vasodilation & vasoconstriction – Improves redistribution of blood – Better at shunting to active muscles Increase in blood plasma • Increases blood volume • Decreases blood viscosity – Blood flows more easily – Enhances delivery of O2 to the muscles