Download Long term responses of exercise on the cardiovascular system

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