Exercise has many health benefits.

Publications International, Ltd.

When you exercise or compete in sports, you notice several things about your body. You breathe heavier and faster, your heart beats faster, your muscles hurt and you sweat. These are all normal responses to exercise whether you work out regularly or only once in a while or whether you are a "weekend warrior" or a trained athlete. When you watch world-class athletes compete, you see the same responses, only magnified.

­The body has an incredibly complex set of processes to meet the demands of working muscles. Every system in the body is involved. In this article, we will look at how your body responds to strenuous exercise -- how muscles, blood circulation, breathing and body heat are affected. You will also see how these responses can be enhanced by training.