Sports Drinks: What, When, and How Much

Should you be lugging a bottle of commercial sports drink to your child's soccer game? What drinks provide the best nutrition for optimal performance? The answers to these questions depend upon how long and how strenuous the exercise is. If you or your child exercise moderately for less than an hour, plain water is the best source of fluids. Water is absorbed more rapidly than any other liquid, but once you begin adding stuff to water, the absorption slows. Drink ahead. Drink a few glasses of water before a game. During the game, drink enough to quench thirst, and after the game drink enough water to quench thirst and then drink at least two more glasses, since thirst is not a reliable indicator of adequate hydration. For high endurance exercise lasting longer than 90 minutes, you will probably need a carbo-lyte-hydration drink (i.e., one containing sugar, salts, and water).

During strenuous exercise lasting more than one hour sports drinks help prevent dehydration, a major cause of muscle fatigue. The main nutritional elements in a commercial or homemade sports drink are water, carbohydrates, and electrolytes (sodium and potassium).

Try these carbo-hydration tips to enhance performance, and therefore enjoyment, of sports.

• Avoid junk juice "drinks," which contain a tiny bit of juice and a lot of added sweeteners. Instead, use "100 percent juice."
• Avoid carbonated drinks, which can leave the athlete feeling bloated.
• Before the game, instead of soft drinks, drink plain water. Besides the sugar in the soft drink slowing the absorption of much needed water, it could trigger low blood sugar during the game, just what the athlete doesn't need.
• Instead of commercial sports drinks, you could make your own. Juices, such as apple, orange, or grape are an excellent base for sports drinks, since they contain both glucose and fructose sugars, as well as potassium, which is lost with sweating. Fructose sugar is one of the best carbohydrates for replacing used up muscle glycogen stores. Add one tablespoon of salt (to replace the sodium lost while sweating) to a quart of dilute juice, and you've made your own sports drink.
• The best time to drink commercial or homemade sports drinks is during exercise, since the carbs in the drink do not cause high blood sugar fluctuations because insulin is not secreted during exercise. (Drinking a high-sugar drink prior to exercise may trigger insulin and lead to hypoglycemia in the middle of the game.)
• As a general rule, sip one quart of cool rehydration liquid per hour of strenuous exercise.
• It's better to drink liquid calories rather than solid food during exercise, since solids remain in the stomach longer and delay the absorption of the much-needed carbs and water.

  A useful reference for eating and drinking wisely during exercise is: Nancy Clark's Sports Nutrition Guidebook, Human Kinetics Publishing, 1996.