What should I eat before I exercise? is the most common question athletes ask me, a sports nutritionist. The answer varies, depending on:
–how hard you will be exercising. Before intense the exercise, you’ll want just a small lowfat snack that digests quickly, such as a half a bagel—as opposed to a whole bagel with peanut butter.
–how well your intestinal tract tolerates food. Some people have cast-iron stomachs and can eat anything pre-exercise, without fear of intestinal distress. Others need to wait a few hours.
–how long you will be exercising. If you plan to exercise for more than 60 to 90 minutes, eating a pre-exercise meal or snack will enhance your stamina and endurance. Pre-exercise food is less important before a 30-minute exercise session (assuming you are not hungry.)
Because each person has a unique response to pre-exercise food, you will want to experiment with a variety of options. Carbohydrate-based foods (such as bread, watermelon, boiled potato) digest easily and are generally the best options. Some popular choices include:
- Toast (or a bagel) with jam or peanut butter
- Banana
- Cereal with lowfat milk
- Oatmeal with raisins
- Granola bar
- Fruit smoothie (made with 1 large banana, ½ cup berries, ½ cup low-fat milk or yogurt) and ice cubes.
- Pita with hummus
Most active people easily tolerate 200 to 300 pre-exercise calories before a 60-90 minute workout; the fuel helps keep blood sugar from dropping and abates the appetite. No need to exercise hungry! If you want to get mathematical, target about 2 calories of carbohydrates per pound of body weight (0.5 g carbs per lb). That means, if you weigh 150 pounds, you want approximately 300 calories (more or less) in carbohydrates.
Adding a little fat or protein to the snack can help with satiety and flavor, but the carbohydrates are the most important factor here. Also, too much protein or fat can sit in the stomach, and contribute to discomfort. While a few nuts in a handful of trail mix can be fine, the dried fruit is the better energizer.
Some people with digestive concerns allow three to four hours between fueling and exercising; others can eat and exercise five minutes later. You may want to allow 2 to 3 hours after a moderate-sized pre-exercise meal to allow enough time for digestion and absorption. You can likely tolerate a smaller (200 to 300 calorie) snack within an hour pre-exercise. If you don’t have any trouble exercising with food in your stomach, you can shorten this window to five minutes! And as long as you are exercising at a pace that you can maintain for more than half an hour, your body can digest the food and use it to fuel your workout.
If pre-exercise food “talks back to you,” start with small amounts of food (a cracker or a piece of banana), so you can train your GI tract to accept some fuel. Even a little food can improve energy and performance. Some people choose a sports drink because it feels less heavy in the stomach. The overall goal, however, for exercise longer than 60 to 90 minutes, is to train your body to be able to tolerate a pre-exercise snack or meal. You cannot run a marathon on air!
For more information: Nancy Clark’s Sports Nutrition Guidebook