TEMPERATURE DURING EXERCISE
Gabe Mirkin, M.D.
You sweat more after you finish exercising than you do while you exercise. You are also more likely to pass out from heat stroke immediately after you stop than during strenuous activity.
More than seventy percent of the energy that powers your muscles is lost as heat, causing your body temperature to rise during exercise. To keep body temperature from rising too high, the heart pumps heat in blood from muscles to skin, you sweat which evaporates to cool your body.
Sweating is controlled by the temperature of the blood flowing to the the part of the brain called the hypothalamus. When your temperature rises, you sweat more. During exercise, your heart beats rapidly to pump blood to bring oxygen to muscles and hot blood from muscles to the skin where heat can be dissipated. When you stop exercising, your heart immediately slows down, so less blood is pumped to your skin, and your temperature rises higher and you sweat more. If you are already overheated, this extra heat can cause you to pass out.