If you exercise in the morning, get up early enough to eat breakfast — that may mean one to two hours before your workout. Most of the energy you got from dinner the previous night is used up by morning, and your blood sugar may be low. If you don't eat, you may feel sluggish or lightheaded when you exercise. If you plan to exercise within an hour after breakfast, eat a lighter breakfast or drink something to raise your blood sugar, such as a sports drink. Emphasize carbohydrates for maximum energy.
Be careful not to overdo it when it comes to how much you eat before exercise. The general guideline:
Large meals. Eat these at least three to four hours before exercising.
Small meals. Eat these two to three hours before exercising.
Small snacks. Eat these an hour before exercising.
Eating too much before you exercise can leave you feeling sluggish, or worse, with a case of diarrhea or stomach cramps. Eating too little may not give you the energy to keep you feeling strong throughout your workout.
Most people can eat small snacks right before and during exercise. The key is how you feel. Do what works best for you. Snacks eaten soon before exercise probably won't give you added energy, but they can help keep up your blood sugar and prevent distracting hunger pangs. Good snack options include:
Energy bars or drinks
Bananas or other fresh fruit
Whole-grain bagel or crackers with peanut butter
A healthy snack is especially important if you plan a workout several hours after a meal.
To help your muscles recover and to replace their glycogen stores, eat a meal that contains both protein and carbohydrates within two hours of your exercise session if possible. If you aren't hungry after your workout, drink juice or a sports drink to provide replenishing carbohydrates.
Good post-workout food choices include:
Yogurt and fruit
Peanut butter or meat sandwich
String cheese and crackers
Nuts and dried fruit
A regular meal with meat, starch, and cooked vegetable or salad