Cardiac Drift

Cardiac drift refers to the gradual increase in heart rate that occurs during prolonged exercise, even if the effort intensity remains the same. This happens because your body needs to circulate more blood to dissipate heat and replace fluid lost through sweating. As your blood volume decreases and your core temperature rises, the heart compensates by beating faster to maintain adequate blood flow and oxygen delivery to muscles. Essentially, it’s your body's way of adjusting to ongoing physical demands and changing internal conditions during extended activity.