What to eat: Getting the right fuel for your best performance

Food provides your body with necessary energy. To make the most of your workouts, focus on:

Carbohydrates: Your body's chief source of fuel

You'll feel better when you exercise if you eat foods high in carbohydrates and low in fat. Your body stores excess carbohydrates as glycogen — primarily in your muscles and liver. Your muscles use stored glycogen when needed for energy.

Cereals, breads, vegetables, pasta, rice and fruit are good sources of carbohydrate. But right before an intense workout, avoid carbohydrates high in fiber, such as beans and lentils, bran cereals and fruit. High-fiber foods may give you gas or cause cramping. Fructose, a simple sugar found in fruit, can increase the tendency for diarrhea with high-intensity exercise.

If you don't like to eat solid foods before exercising, drink your carbohydrates in sports beverages or fruit juices. "Research shows it makes no difference in performance whether you drink your carbohydrates or eat them," says DeBoer. Do what feels best to you.

A diet containing at least 40 percent to 50 percent of calories from carbohydrates allows your body to store glycogen, but if you're a long-distance runner or you exercise for long periods of time, you might want to consume more carbohydrates regularly and consider carbohydrate loading before a big athletic event.