Physiology L3

Aim The aim of today’s lesson is to identify the Adaptations to long term exercise

Long term exercise?? Long term exercise is also known as chronic exercise (participating in exercise for more than eight weeks) We know the initial responses of exercise , we know how the bodies responses to long term exercise, but how does the body ADAPT to endurance training.

Cardiovascular ADAPTATIONS Increase in delivery of oxygen to the working muscles, this is the main adaptation to the cardiovascular system. If you were to dissect the heart of a top endurance athlete you would find that the left ventricle walls were a lot larger than the right What is this called?

Cardiovascular ADAPTATIONS This adaptation is called CARDIAC HYPERTROPHY Cardiac hypertrophy is the first adaptation to the cardiovascular system from endurance training Cardiac Hypertrophy = the size of the heart wall becomes thicker and stronger

Cardiac Hypertrophy Adaptation occurs in the same way that we increase the size of our skeletal muscle – the more we exercise our muscles the larger they become. In the same way, the more we exercise or heart muscle through aerobic training the larger it will become

Cardiovascular ADAPTATIONS Cardiac Hypertrophy will have an effect on increasing stroke volume (amount of blood pumped out per beat) As the heart wall becomes bigger, it can pump more blood per beat, as the thicker wall can contract more forcibly (Starlings Law)

Cardiovascular ADAPTATIONS As the stroke volume is increased, the heart no longer needs to beat as often to get the same amount of blood around the body. This result in a decrease in heart rate is known as BRADYCARDIA Bradycardia is the decrease resting heart rate

Bradycardia E.G. Lance Armstrong has a resting heart rate of 30 beats per minute As stroke volume increases cardiac output also increases, so an endurance athlete’s heart can pump more blood per minute than a sedentary persons

Capillarisation HOWEVER , resting values of cardiac output do not change. This is due to the athlete having more Capillaries allowing more blood to flow to the working muscles. This is called CAPILLARISATION

Cardiovascular ADAPTATIONS An increase in Haemoglobin due to an increase in the number of red blood cells (which contain haemoglobin) further aids in the transport of oxygen.

Cardiovascular ADAPTATIONS Haemoglobin content rises = increase in blood plasma = blood haematocrit reduced ( ratio of red blood cell volume to total blood volume) Which blood haematocrit reduced and enables the blood to flow freely

Recap Cardiac Hypertrophy Bradycardia Capillarisation

Haemoglobin content rises Increase in blood plasma Blood haematocrit Blood flow freely

Aim The aim of today’s lesson is to identify the Adaptations to long term exercise