You're itching to cool off in the pool, butyou've just chowed down-now what? If youfeel up to it, dive right in! "Swimming on a fullstomach won't make you more likely todrown," says Christine Keating, M.D., a physicalrehabilitation specialist at the Ochsner HealthSystem in New Orleans. The reasoning behindthat misconception is that digestion routes bloodto your stomach, thereby robbing your musclesof oxygen, which can trigger a side or leg cramp."But during exercise, your body producesadrenaline that actually boosts your circulation,supplying your muscles with oxygen," saysKeating. In fact, you shouldn't swim on an emptystomach. Before you take the plunge, Keatingrecommends drinking water and eating a100- to 200-calorie snack.