You don't need a fancy sports drink to recover quickly from a short workout and be ready for your next session. Instead, consider the potent recovery drink that's probably already in your fridge: skim milk. It rehydrates exercisers as well as water does, and more effectively than sports drinks. Try it for a workout that lasts less than 2 hours (if it goes longer than that, we prefer you use sports drinks).

When you exercise, you deplete water and glycogen, the fuel that allows your muscle cells to come together or, as we say, shorten or contract. Being depleted of these things is like being starved of sleep: Your body just won't perform as well. Being just 2% dehydrated reduces exercise performance and makes your workout feel harder. That's why rehydrating is so important.

Milk may do more than that: There's evidence that weight lifters who drank a 16-ounce glass of milk right after a workout, and another glass an hour later, gained more lean body mass and lost more fat than the lifters who instead drank a soy or carbohydrate sports drink. But we agree -- that's a lot of milk (and its calories may be more than you burned off during exercise). So next time you work out, try a single glass afterward and see if it makes your next workout feel even better.