Q. What's the best way to rehydrate after exercise?

A. Drinking plain water works just fine for mild or moderate exercise (less than 60 minutes). But if you're exercising more than an hour or during very hot weather, you would do well to consider a sports drink.

Sports drinks rank above water for rehydrating the body in two key ways: Their salt, or electrolyte, content speeds fluid absorption in the body; and their often sweet flavorings encourage drinking greater quantities. A recent study found that even low-fat chocolate milk works just as well as your average sports drink. Why? It has a great ratio of fluid, carbs, and protein.

No matter what beverage you choose, it's a good idea to start hydrating before exercising. The rule of thumb is to drink two glasses of water or other fluids over the course of about two hours before exercise—allowing yourself a chance to use the bathroom before you set out.

Most recreational athletes don't drink enough during exercise to keep up with sweat losses. So train yourself to become a better drinker: Keep a bottle of water or another drink with you at all times and sip regularly, especially if you notice any thirst.

This Q&A was written by Victoria Dolby Toews, MPH, a health journalist based in the Pacific Northwest, where she and her family enjoy hiking and cycling.