Do you eat before you work out? This question sparks a lot of controversy; I meet clients and fitness experts alike who are on both sides of the fence. Some are convinced that working out on an empty stomach optimizes fat burn, while others claim that working out without fuel does more harm than good.
Let’s take a closer look at each argument.
PROS: Really, there is one primary argument for eating before exercising, and it’s kind of a big deal: our bodies need energy to perform. You wouldn’t expect your car to run on empty, so don’t expect your body to, either. Food is fuel. Without it, you risk running into the following problems:
– Sluggish workouts; you can’t push your hardest and get the most out of exercise
– Protein losses; in the absence of other sources of energy, your body may need to break down muscle to meet demand
– Injury (theoretically, at least)
– Low blood sugar and dizziness, particularly if you have diabetes
– Slowed metabolism, which can occur if your body perceives the stress of energy demand (what you burn) to greatly exceed the amount of energy available (what you’ve eaten)
– Potential overeating afterward, though the research is mixed on this one
– Eating too much too close to a workout can also cause sluggish workouts; the energy isn’t yet absorbed for the body to use, and in fact, digestion slows dramatically during exercise, which can cause discomfort and cramps.
– Exercise does not burn that many calories, so a pre-workout meal or snack could very easily “cancel out” the calories burned in a workout, which is particularly troublesome if your goal is weight loss.
THE BOTTOM LINE: FIT!
Although there are arguments to be made for both, there are more benefits to eating before exercising than there are risks, and vice versa. However, it’s equally important to consider the amount and timing of the food to maximize the benefits of a pre-workout snack and minimize the unwanted side effects:
– If it’s time to exercise and you ate a full, well-balanced meal in the past three hours, you don’t need an extra snack. A well-balanced meal contains adequate calories, protein, fiber-rich carbohydrates, and heart-healthy fats.
– If your workout is scheduled for more than three hours after a meal, consider a small, easily digestible snack about an hour before the workout. This should consist mostly of simple carbohydrates with a little bit of protein (a cup of yogurt or an apple with a hardboiled egg, for example); keep fat and fiber to a minimum, as these can slow digestion. (Normally, slow digestion is awesome, but right before a workout, it’s a recipe for discomfort.) And remember, if your goal is weight loss, these calories are part of your daily needs, not in addition to them.
– If you’re a morning workout kind of person who doesn’t want to wake up an hour earlier to allow for complete digestion of a pre-workout snack, try liquid forms of carbohydrates at least 15 minutes before starting your workout. A glass of low-fat milk is my favorite recommendation, but 100% fruit juice works, too.
Consider the intensity and duration of your workout. If you’re taking a light stroll around the park for an hour, you probably don’t need to worry too much about fueling up. If you’re going to a kickboxing class or are about to run a 5K, then yes, you should probably avoid doing it on a totally empty stomach. I’ve worked both with clients who insist on snacks to fuel their 45-minute leisurely walks and those who attempt three-mile runs immediately upon waking up. Neither is ideal.
In the end, you may need to experiment a little to find the right timing, amounts, and specific foods for you. Pay attention to how your body responds to different combinations. Do you feel energized after peanut butter and a banana, or a little sluggish? Do you try to go for a run first thing in the morning, only to wind up fading or feeling a bit out of sorts? That’s your body telling you that it’s time to try something different.
Remember, food is fuel. Calories are not the enemy, but too often we underestimate what we eat and overestimate what we burn. And, if you stop to listen to it, your body may well be the best tool you have in this crazy game called life. It’s about time we sat up and paid attention to what it has to say.