You've seen the promises on energy bar labels and sports-drink cans—marketing slogans that pledge those products are just what you need to improve your exercise results.
Whether your favorite physical activity is walking at a moderate pace or cycling competitively, eating and drinking right can help sustain your endurance. Yet you may not need specially formulated foods or liquids to keep your body going strong.
During exercise, you sweat and lose fluid, your blood sugar drops and your muscles use stored carbohydrates. All three need to be replenished or you'll run out of stamina.
Always drink some cool water at least 20 minutes before starting your activity. For endurance sports such as long-distance running, swimming, cycling or cross-country skiing, also drink two cups of fluid two hours beforehand to reduce the risk of dehydration. Fruits and vegetables eaten before, during and after exercise provide additional fluid.
If you exercise less than 60 minutes per session, take small sips of cool water every 15 minutes. For those who exercise more than 60 minutes at a time, commercial sports drinks containing four to eight percent carbohydrates may also be used. Avoid "energy" drinks made of mostly water, sugar and caffeine.
Having a small snack before exercising is a good idea. To get the carbohydrates you need, choose easily digestible, high carbohydrate foods—whole grains, nuts and seeds, bananas, orange slices or dried fruit. Have a low-fat, high carbohydrate snack (fig bars, cereal, graham crackers, apple juice) about 30 minutes after exercise.
What about energy bars? Read the labels carefully to avoid those that are loaded with fat. For exercise sessions less than an hour long, you don't really need an energy bar. If you use them, the American College of Sports Medicine suggests choosing bars with 25-40 grams of carbohydrate and less than 15 grams of protein.