When Do You Need a Sports Drink?
For: Pop Quiz on Water,
May 2003
Sports drinks, according to the Journal of the American Dietetic Association, have probably been researched more intensively than any other topic in sports nutrition. If you run, jog, or work out at a gym, perhaps you down a sports drink before, during, or after your activity. Or you may see other exercisers downing their Gatorade or Powerade. You may stick to plain water—and many athletes do just that. Who is better off?
When you're doing sweaty exercise, it's important to drink fluid. Your body needs it. As we've said, thirst may not be a reliable indicator of your fluid needs while exercising. A loss of fluid equal to more than 2% of body weight (for a 150-pound person, that's 3 pints, weighing 3 pounds) can bring on dizziness or headache and actually impair athletic performance. If you're cycling, running, or doing strenuous hiking, you can lose a quart of water in a hour. Hot weather can make you lose fluid faster, and so can cold, dry weather.
How you can best replace the lost fluid depends on many things. Sports drinks have some advantages over water. For years most exercise physiologists have recommended water as the ideal replacement fluid and have cautioned that sugar tends to slow down absorption of beverages. Sports drinks, however, are formulated to contain no more than 8% sugar—the right amount to improve performance without slowing absorption.
Sports drinks can help you conserve your carbohydrate stores and delay fatigue during a prolonged workout or competition. They also have enough sodium and potassium to replace what you lose in heavy sweating. Sodium and potassium are electrolytes; they help maintain an optimal fluid balance in the body. A key reason for flavoring sports beverages is to motivate you to drink more.
It's also true that a normal diet will supply the carbohydrates, sodium, and potassium you need when you exercise. If you are doing moderate exercise for an hour or less, you don't need the boost of a sports drink—water is fine. If you are participating in an endurance activity such as running a marathon, or if you are exercising strenuously for more than an hour, consider a sports drink.
Do remember to drink frequently before, during, and after your workout. By the way, it's best to avoid carbonated beverages during endurance exercise.
Do-it-yourself sports drink
Sports drinks are expensive. If you would rather make your own, dissolve a tablespoon of sugar and a pinch of salt in a tablespoon of orange juice or in 2 tablespoons of lemon juice and add 7.5 ounces of cold water. This mix has all the benefits of a sports drink.
UC Berkeley Wellness Letter, March 2000