During exercising, your body's temperature levels up and one of the body's mechanisms of homeostasis is perspiration, which is sweating. Sweat helps cool off the body by excreting the heat to the exterior surface f the body and it gets rid of excess fluids and salts. The breathing rate also gets higher due to the physical activity. Blood flow will increase as well, as the blood vessels dilate and get wider allowing more blood to pass through.
