Question

Why is the cardiac output of an athlete higher than an ordinary man?

Answer 1

Cardiac output is direct measurement of cardiac activity which is the amount of blood flowing through the heart towards the body. As we all know athletes do rigorous exercise therefore they require more oxygen in order to give energy to their body for this their cardiac output increases more then a ordinary person as they require more blood to flow from heart.
Cardiac output increases with exercise therefore athletes have higher cardiac output.