Synching your meals and snacks with your workout can get complicated—or at least feel that way. You want to have enough food to push you through, but don’t want to eat so much that you feel nauseous. Finding that middle ground between hungry and full is the sweet spot. You need to find the middle ground: enough energy to crush your workout. But that doesn’t mean that you always need a snack or meal before you get moving. Here, dietitians break down what you need to know about fueling before your workout. Find out if you’re eating enough or too much before your sweat sesh.
When You Should and Shouldn’t Eat Before Your Workout
You can exercise on empty, particularly if you want to burn through stored-up energy, says Pam Bede, RD, nutrition expert with SwimBikeRunEat.com. But, you probably don’t want to if you’re about to have an intense session or exercise for over an hour. In those cases, you risk hitting a wall if you don’t have enough gas to keep going.
“If I have a client who has one main goal and that’s weight loss, I often recommend a bout of fasted cardio [aka working out without eating beforehand, likely first thing in the morning] in order to tap into their reserves,” Bede says. “But, if she continuously can’t crank through a workout because she’s running on empty, it may be better for her to have a small snack in the 30 to 60 minutes beforehand. The overall calorie burn is often greater.” So, that’s the catch with skipping a meal pre-workout. You could feel lower on energy and therefore, not work as hard.
Torey Armul, RD, registered dietitian and spokesperson for the Academy of Nutrition and Dietetics, says that if you’re starving, go for a snack. “There’s no need to be full before a workout, and there’s no need to fuel an easy 30-minute workout, especially if you’ve eaten recently. However, I do recommend eating something if you feel starving, if you haven’t eaten for more than five hours, or if you’re doing a long or intense bout of exercise,” she says. “Our bodies have an internal supply of glucose, but we burn this stored energy throughout the night while we sleep. There’s limited glucose left in the morning to properly fuel a morning workout. Eating something before a workout gives your body glucose for energy and minimizes fatigue during the workout.”
Also, your body converts fat to energy more slowly in a fasted state. So that’s why you might feel a little slower sans carbs, Armul explains.
Signs That You Should Have Eaten Before a Workout
Figuring out what works for your body and what helps you achieve your goals is a personal process. So, if you didn’t eat before and you find yourself weak, light-headed, or like you’re half-assing a workout, it’s likely a sign to get that snack before your next sweat. “If your energy is waning during the workout or you want to call it quits, chances are that you should’ve eaten more—or differently—beforehand. Your fuel reserves are low,” Armul explains. Bede also mentions that if you do a workout that you normally can achieve, but without food, you can’t, that also means you want a snack pre-sweat.
If you feel light-headed, that could mean your blood sugar is low, says Mitzi Dulan, RD, co-author of The All-Pro Diet: Lose Fat, Build Muscle, and Live Like a Champion. In that case, you definitely need some glucose (aka carbs) beforehand.
The Best Foods to Eat Before a Workout
If you’re having that small meal, a combination of protein, carbs, and healthy fats is best, says Dulan. Her favorite: a honey, peanut butter, and banana open-faced sandwich on whole wheat bread. Or, protein balls made with oats, honey, peanut butter, chocolate chips, and almonds.
For a quicker snack, carbs are preferred, with a bit of protein, Armul says. “Portion control is critical pre-workout, so you don’t overload your digestive system,” she says. Some of her go-to’s include avocado toast, peanut butter and jelly, carrots and hummus, cereal with milk, trail mix, or a homemade smoothie.
Also, Bede notes that for strength workouts, your body benefits from having protein pre-lift. “It helps the muscles jumpstart recovery and synthesis after the workout is complete,” she says. “If you can find time for a smoothie, grab some with branched-chain amino acids (BCAAs) and electrolytes and fluids for a mid-workout pick-me-up.”
Bede’s other pre-workout boost: caffeine. “It helps lower perceived effort, aka the workout feels easier,” she says. If you love coffee, then go for it. If you don’t tolerate it well, feel free to skip.
How to Time Your Pre-Workout Fuel
Ideally, you want to give yourself at least 30 minutes to digest your food before a workout—but that’s mostly if you’re eating a small, digestible snack, Bede says.
Giving yourself a half hour, “minimizes digestive discomfort and allows the nutrients to be digested and utilized by exercising muscles,” Armul says. “Eating less than 30 minutes beforehand can lead to bloating and cramping as your body works to digest the food.”
For small meals, it’s probably best to give yourself an hour—two if you’re eating a big dish. Sleep is a very valuable recovery tool, though, says Dulan. So, if you’re working out first thing and don’t have that kind of time, perhaps a smaller snack is better.