If you always feel ravenous after you get out of a pool, rest assured — it's not just you. Exercise works up an appetite, but swimming is extra hunger-inducing because it cools down your body. Photo via VisualHunt
When you're in a cool environment, including a pool that's cooler than body temperature, your body has to work to keep warm. This extra effort seems to be the reason we can't wait to get out of the locker room and into the nearest restaurant with an all-you-can-eat buffet. People who exercise in cold water emerge hungrier than people who do the same workout in warm water. So if you're looking to curb that post-swim urge to eat everything in sight, and you don't have the option of swimming in a warmer pool, try warming up afterwards with a little dry land exercise, like a brisk walk or a few minutes in the sauna.
Why Am I So Hungry After Swimming? [Mental Floss]