“If you’re only exercising for an hour or less at lower intensity, you wouldn’t need to fuel, especially if you had eaten a meal three to four hours prior—but you should still hydrate,” says nutritionist Leslie J. Bonci , MPH, RD, CSSD, LDN. Many people also find that working out with food in their stomach—even if it’s just a small snack—can lead to cramping or gastrointestinal (GI) distress. Those people will delight in learning that more and more research is showing the benefits of working out on an empty stomach, as it allows the body to burn fat (not the carbs you just ate) for fuel.
Eat at least 30 minutes before exercise.
Still, many gym-goers need a little pre-workout bite to feel energized and avoid things like dizziness. “It’s best to aim to have your snack at least 30 minutes before your workout to help top off energy stores for the upcoming activity,” says Cara Harbstreet, MS, RD, LD, of Street Smart Nutrition, a nutritionist in Kansas City. “As a general rule, this snack should be high in carbohydrate, low to moderate in protein, low in fat, and also include 5 to 10 ounces of fluid.”
Eat a snack, not a meal.
It’s important to remember that you want to be eating a snack—not a meal. “When you’re eating before a workout, the goal should be a fist-size, not a plate-size, portion to decrease gut distress,” says Bonci. “If you’re going for the popular option of having a shake, that should be consumed at least an hour before planned exercise to allow time for the food to leave the stomach, so all the blood is not diverted to the digestive tract during exercise, but instead flowing to the exercising muscles.”
Eat for the workout you’re doing.
Before we dive into more specific snack options, it’s worth highlighting that what you’re reaching for might change based on the kind of workout you’re doing. “For HIIT-type workouts, you’re burning more carbs, so your pre-workout fuel should be more carb focused,” says Bonci. “If you’re strength training, ideally you would have some protein not just after your workout, but also before to optimize muscle protein synthesis and minimize breakdown. Whereas for yoga, a small, carbohydrate snack that leaves the gut quickly may feel more comfortable and minimize gut distress, especially if you are doing inverted positions; so eating four prunes or prune puree, and making sure you hydrate an hour before class, would work well.”
What to eat in a pinch
As we all know, there are many days when just getting to the gym is a challenge, so planning a pre-workout snack’s timing isn’t always realistic. If you find yourself in need of some fuel as you’re literally walking into the workout room, Harbstreet recommends avoiding anything high in protein, fat, or fiber, as these can all slow digestion and potentially lead to unwanted GI side effects. “Lightly flavored foods are also less likely to cause issues, so something like lightly salted, roasted petite potatoes can be a great option. Another solution may be turning to liquid fuel sources at this point; they can be quicker and easier to digest and absorb, meaning you get the benefit of the carbohydrates in liquid form as well as hydration support.” Things that break down quickly, like fruit or dried fruit, can also be good in this scenario.
The best pre-workout snack options, according to RDs
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