Health Watch -- Exercise Fuel

Health Watch is a Public Service of the Office of News and Publications and is intended to provide general information only and should not replace the advice of a medical professional. You should contact your physician if you have questions about any of these topics.

What's the best way to recharge your body after exercise?

When you've been exercising, you need to recharge yourself with the right kind of food. But what is the best kind of food?

Because exercise builds muscles, many people assume you need more protein after a workout, but doctors at UT Southwestern Medical Center at Dallas say your muscles need a different kind of fuel.

What your muscles really need are carbohydrates, says Dr. Scott Grundy, director of UT Southwestern's Center for Human Nutrition. Carbohydrates are stored in your liver and muscles as glycogen, and glycogen is what fuels your muscles during exercise. Glycogen from your liver is converted to glucose to give you energy. How long and how hard you're able to exercise depends on how much glycogen your body has stored.

Physical training increases the amount of glycogen your body can store and allows your body to use its fuel more efficiently, but there are still limits. Your body will eventually run out of fuel.

That's why your body needs carbohydrates to refuel itself after a workout. You need carbohydrates so your liver and muscles can store more glycogen. That will help you restore yourself and maintain your energy for peak performance. That's why endurance athletes eat high-carbohydrate meals before and after a race.

You do need some protein to replenish muscle tissue, but you probably get enough protein from a balanced diet. Just about any diet that includes meat will include enough protein.


June 2004