The key to making sure your body fully recovers after a hard workout may be as simple – and bracing – as a cold shower. Over the past few years, pro athletes have found that taking a 10-minute "contrast shower" – alternating between hot and cold – after exercise allows them to perform better the next day.

Here's how to do it: Take a normal five-minute hot-water shower, then for the sixth minute, switch to cold, targeting recently exercised muscle groups. Turn up the hot water for one minute, then repeat as many times as you can stand, ending on cold. "The hot water relaxes the muscles and dilates the blood vessels, increasing circulation," says Mark Twight, mountaineer and owner of Gym Jones, a high-intensity training center in Salt Lake City. "The cold water causes your body to slow circulation in the skeletal muscles and helps your heart pump blood through your body. The rotation between cold and hot dilates, then contracts, your blood vessels, facilitating circulation, the key to recovery."

Twight recommends three rotations, since that's about what most people can stand. But if you're able to do four to six rotations of hot and cold, even better.

"Contrast showers reduce inflammation and pain," says Neal Henderson, director of sports science at Colorado's Boulder Center for Sports Medicine. "I believe in them."