Physical Health

How to Fuel Up Properly

May 7, 2014

cereal3Now that you exercise regularly, you probably have experimented with eating before exercising. Perhaps you have tried not eating at all before your workout but found you didn’t have enough energy to complete your session. Maybe you ate too much right before your session and suffered stomach cramps and felt your legs get heavy. When should we eat, what should we eat and how much should we eat so that our exercise session is efficient? Registered dietician Stephen DeBoer has some specific ideas and recommendations in this regard.

Your body can digest food while you’re active, but not as well as it can when you’re not exercising — partly because your blood is trying to do two jobs at once. “Your blood goes to whatever part of your body needs it,” DeBoer says. When you start exercising, some blood gets taken away from your stomach. Both jobs get done, but not as effectively or as side-effect-free as you’d like.

On the flip side, not eating before you exercise can be just as bad as eating too much. Low blood sugar levels can make you feel weak, faint or tired, and your mental abilities may be affected as well, making you slower to react.

So how do you strike a balance? Everybody’s different, but here are some general rules for timing your eating and exercise:

  • Eat a full breakfast. Wake up early enough to eat a full breakfast. “Most of the energy you got from dinner last night is used up by morning,” says DeBoer. “Your blood sugar is low. If you don’t eat, you may feel sluggish or lightheaded while exercising.” If you plan to exercise within an hour after breakfast, eat a smaller breakfast or drink something to raise your blood sugar.
  • Time your meals. Eat large meals at least 3 to 4 hours before exercising. If you’re having a small meal, you should eat at least 1 to 2 hours before exercising. Most people can eat snacks right before and during exercise. The key is how you feel. Some people feel lightheaded if they eat an hour or less before exercise. Do what works best for you.
  • Don’t skip meals. Skipping meals may cause low blood sugar, which can make you feel weak and lightheaded. The longer your exercise session, the more important that last meal is for keeping your energy level up.
  • Eat after your workout. To help your muscles recover and to replace their fuel stores, eat a meal that contains both protein and carbohydrates within 2 hours of your exercise session if possible.


  1. Low fat
  2. Moderate carbs and protein
  3. Low fiber
  4. Include fluids
  5. Made up of familiar foods that you tolerate well

A grilled chicken sandwich or a slice of pizza might fit the pregame meal description, but stay clear of fried foods (including french fries), greasy burgers, and soft drinks.

Exercisers need a higher carbohydrate intake and should be sure to keep the fats down. The man fuel that you burn in exercise is carbs. The more carbs you eat—the more efficiently your body will use them. Cereals, breads, vegetables, pasta, rice and fruit are good carbohydrate sources (try to stick with the unrefined variety of grains—whole grains). But right before an intense workout, avoid carbohydrates high in fiber, such as beans and lentils, bran cereals, and fruit. The fructose in fruit can increase the tendency to have diarrhea with hard exercise, and high-fiber foods may give you gas or cause cramping

As far as what to eat after exercise, protein is a good choice, but don’t overdo it. 10-20 grams is more than enough.

Drinking water is essential before, during and after exercise and it is important to maintain a high level of hydration while exercising. According to the guidelines issued by the American Council on Exercise, one should drink 2 cups of water within an hour before exercising, consume 4-8 ounces of fluid every 10-15 minutes during the workout, and consume 2 cups of fluid for every .5 kilogram lost during exercise at the conclusion of the workout. One should never lose more than 2% of his body weight due to dehydration. This is dangerous and can affect your performance. For those living in the Middle East, remember that we live in a hot and sometimes very dry climate, and therefore need to be extremely careful to drink enough in the summer months.

How do you know if you are beginning to dehydrate? Don’t rely on your thirst reflex. If you’re thirsty, you’ve already waited too long before drinking. Urine that is a dark, gold color indicates that you are not drinking nearly enough. One quick tip on maintaining good hydration: Every time you are ready to eat one of your meals or snacks, drink 2 cups of water before and 2 cups after. This will ensure that you stay hydrated and healthy.

It always pays to keep in mind that our food is our fuel. You wouldn’t put in bad gasoline or oil in your car if you want it to run well, so be just as careful about what you eat, how much you eat and when you eat before and after exercise. Being careful about your food intake before exercise will “add hours to your days, days to your years, and years to your lives.”