Why do swimmers shave their entire body?

They shave their entire body so they can move through the water faster.

-Lack of hair has nothing to do with speed for swimmers (or very little). When you shave your body, you are not only removing hair, but the layer of dead skin cells on the top of your skin as well. The idea is to remove all of the gunk and buildup on your skin so that when you enter the water, it feels different. Basically, all of the stimulation gives your body a shot of endorphins when you dive into the pool (kind of like steroids, without the drugs). That is why people swim faster after just shaving.