To Eat or Not to Eat

Is it better to eat before the gym, or to wait until after you’ve worked out? 

Rodale asks the question to eat or not to eat before a workout: It’s a question that has perplexed gym rats for years. The idea is that not eating before exercise forces your body to shift from quick burning carbohydrates (which you usually get from food) as a source of fuel to the fat stores you want to burn off. But that argument doesn’t hold water, says Brad Schoenfeld, MS, CSCS, president of Global Fitness Services, a consulting firm, and professor in the department of exercise science at Lehman College in New York. “It’s a shortsighted way of looking at how your body works,” he says.

Schoenfeld analyzed the research that’s been conducted on how our bodies function during exercise and concluded that, whether you eat or don’t eat before exercise, research shows your body burns the same amount of fat. And working out on an empty stomach can actually cause muscle loss, he adds, if you do it on a regular basis. When you’re hungry, your body goes into survival mode and draws protein away from muscle, where it’s less crucial to survival, than from your kidneys and liver, where the body normally looks for protein. “Your body cares more about survival than looking good at the beach,” he says. As a result, you lose muscle mass, which can, over time, suppress your metabolism and make it harder to lose weight.

On a more basic level, he says, exercising on an empty stomach means you don’t have the energy to put in a really good workout. “One of the benefits of aerobic exercise is doing it at a higher intensity,” he says. “If you’re just getting out of bed, slogging through your exercises like a zombie, you won’t be able to get that intensity.”

Tempting as it may seem to cut down on calories before you head into a big calorie-burn session, you’re not doing yourself any favors. You aren’t giving yourself the fuel you need to last through a 30-minute or hour-long workout, and you could be losing muscle mass while you’re at it. “You’re just spitting in the wind,” jokes Schoenfeld.

Here are Schoenfeld’s suggestions:

• First, decide when you’re working out. To get in that recommended 150 minutes of exercise a week, you have to designate a time that works for you. You may think that working out in the morning will allow you to get it out of the way, but if you’re not a morning person, you could be making yourself miserable, he says. “Let your biorythms dictate when you exercise,” he says. If you feel better using exercise as a de-stressor after work, go in the evenings. Or, see if taking a midday break and exercising during your lunch hour is easier. If you still don’t know, use these tips to determine your exercise personality.

• Then worry about what to eat. The best pre-workout snack contains some form of healthy complex carbohydrate and a protein, Schoenfeld says. If you’re working out in the morning, a good breakfast might be a bowl of oatmeal and a hardboiled egg. For late-day exercisers, a turkey sandwich with whole grain bread or a lunch of chicken with brown rice will work.

• Time your snack. It’s not just what you eat, but when you eat it that’s important. “One and a half to two hours prior to working out is the ideal time to have a snack,” he says. That allows your body enough time to digest your food. If you snack close to when you exercise, the food will just sit in your stomach, he says. When you’re digesting food, your gut needs blood to do that, but when you start exercising, that blood gets redirected to your working muscles. “Your body takes blood away from the area where the food is and you end up getting a cramp.” If you do find yourself starving a few minutes before a workout, he suggests drinking some fruit juice with added whey protein. Your body requires more energy to break down whole foods, he adds, but liquids go through your system and provide you with energy much more quickly.