Everyone has had that moment of pure regret. You know, the one where you start jogging, lifting weights, or jumping into downward dog, and then quickly realize what you ate pre-workout was a horrible idea. You don’t have to hit the gym on an empty stomach, though—you just have to choose your energy sources wisely.
While munching on the wrong foods can lead to everything from gas and bloating to diarrhea and feeling sick to your stomach, going with a safer option can help you power through your sweat sesh and get through every nep. “We often think about what to eat after a workout, but nutrition before exercise can be just as important,” says Amy Gorin, MS, RDN, owner of Amy Gorin Nutrition in the New York City area.
The next time you want to eat before working out, keep things simple by grabbing a quick snack about an hour before you exercise: “I recommend eating a small amount of protein and some easy-to-digest carbs. Your body will utilize the amino acids in the protein instead of breaking down the protein in your muscles, and the carbs will help you power through your workout,” Gorin says. So whatever you do, skip these 20 foods and instead have something a little more workout-friendly. Your body will thank you—promise.
1. Baked Goods
If your pre-workout meal typically involves eating a blueberry muffin on the way to the gym, put down the baked good: It’s only going to do your body harm—and make you fall asleep during your sweat sesh. “High-glycemic foods—including refined white sugar and baked goods—cause a quick rise in insulin with a subsequent quick drop in blood sugar. That is known as hypoglycemia, the typical crash you experience after eating refined carbs and high-sugar foods,” says Robert Zembroski, MD, functional medicine specialist and author of Rebuild. “Foods that raise blood sugar also raise insulin levels, and this often can make you more tired.” Want to curb your sugar intake? Grab a copy of The 14-Day No Sugar Diet to get healthy swaps, grocery lists, recipes, and much more!
When you’re deciding what to toss into your morning smoothie, kale might seem like a no-brainer. The only problem? Your stomach might not agree. “Sure, kale is the ultimate health food, but is it really going to help you crush that workout? No way,” says Michelle Cady, health coach and author of Self-Care in the City. “Fibrous cruciferous veggies require your digestion to go the extra mile breaking down their tough cell walls. And since your digestion mostly stalls or shuts down while you’re engaged in a hard workout, eating cruciferous vegetables can lead to bloating, gas, and discomfort in your digestive tract.”
3. Sugar-Free Candies
Anything sugar-free seems like a safe bet pre-workout, but that’s not the case. To make up for the sweetness, other additives are included—and they’re ones your stomach definitely won’t agree with. “Many sugar-free foods contain sugar alcohols, which can cause gastrointestinal distress—really, the last thing that you want right before or during a workout,” Gorin says.
If you feel bloated and lethargic after drinking milk, you’re not alone. Unfortunately, that’s just one of the many reasons to avoid it before working out. “Serious athletes and weekend warriors should avoid milk and milk-based foods; they contain lactose—the sugar found in milk,” Dr. Zembroski says. “For many people, lactose intolerance will cause bloating, gas, and often diarrhea from bacterial fermentation of lactose.” Aka all things you don’t want to deal with during your HIIT session.
You’re already losing water during your workouts from all that sweat your body is unleashing, so why dry out your body even more with booze? Skip out on sipping wine before yoga and chug some water instead. “Alcohol is dehydrating, so save the glass of red vino for after dinner,” Gorin says. “And of course exercising while under the influence isn’t exactly safe. You want to get stronger—not hurt yourself.”
Kale isn’t the only fibrous cruciferous veggie to avoid before you work out. According to Cady, cauliflower is another culprit that can result in blowing up like a balloon while you’re exercising. To make sure you get your workout and nutrients in, she suggests saving the high-fiber veggie for after your workout—or just “give yourself a three-to-four-hour window to rest and digest before you start exercising.”
You might want to reap the benefits from chugging some caffeine before your workout, but soda is one of the worse ways to get your energy fix. “Carbonated beverages contain gas bubbles, which can fill you up. And feeling full during a workout isn’t the greatest thing, because it might cause you to not hydrate properly with regular ‘ol water—or sports drinks if you need them,” Gorin says.
Beans, beans, the musical fruit—the more you eat, the more you…well, you know. According to Zembroski, while they’re an excellent source of carbs and protein, they’re hard for your stomach to handle before exercising. “Unfortunately, some people lack the enzyme, alpha-galactosidase, which is needed to break down beans and cruciferous vegetables,” he explains. “After eating these beans, bacteria in the gut helps break them down. That process produces large amounts of carbon dioxide and hydrogen, causing bloating, gas, and pain—a situation you don’t want at the gym.” There is a solution, though. If you want to get your plant protein fix pre-workout, Zembroski says you can help prevent the discomfort by taking a supplement containing the missing enzyme.
9. Brussels Sprouts
With 3.3 grams of fiber per cup, Brussels sprouts will definitely keep you full and satisfied until your next meal. Unfortunately, that’s going to lead to a very upset stomach if you decide to work out right after gobbling them up, though. According to Cady, they could lead to gas and bloating right in the middle of your training session.
Milk is one thing, but how about cheese? Since, by definition, it’s made by curdling milk, it’s also not a safe option to eat before a workout. “Although lactose ‘intolerance’ is completely normal since adults are not supposed to drink milk, it’s a very good idea to refrain from consuming any milk-based products before jumping on the treadmill,” Zembroski says.
11. Sparkling Water
Soda is a bad choice pre-workout, but it’s not the only bubbly beverage to avoid. Even though sparkling water is a healthier choice, it’s still not going to do your stomach any good if you’re about to exercise. “I’m a huge fan of seltzer and sparkling water, but I always recommend avoiding carbonated drinks right before or during a workout,” Gorin says.
Soy is one of the most popular—and effective!—ways to get your protein via plants. But with that being said, you might want to save it for a post-workout meal. According to Zembroski, consuming foods that are made from unfermented soy—like protein bars and powders—that still contain the antinutrients before fermentation can result in “reduced protein digestion, bloating, and gastrointestinal discomfort.”
If you haven’t given cabbage a chance yet, it’s time. Not only does it add a serious crunch to every dish (hello, best tacos ever), but it’s also tasty on its own, making for the perfect midday pick-me-up. But if you want to chomp on it bunny-style before a workout, think again. According to Cady, it can cause some discomfort just like the rest of the cruciferous vegetable gang due to all the digestion it requires.
14. Junk Food
Whether it’s pizza or French fries, fried or greasy foods will make you feel crappy anytime you eat them. So chowing down on them right before you hit the gym is an especially bad idea. “Protein and carbs are the macronutrients that are going to help your workout. So there’s no reason to load up on fat, especially saturated fat, right before a workout,” Gorin says. “Plus, if you eat a lot of fat in one sitting, that could slow your digestion, which would cause your body to more slowly utilize those proteins and carbs.”
15. Fruit Juice
Drinking a big glass of orange juice might seem like a great way to kick off your morning, but not if you’re about to head off to your favorite exercise class. “There are two main reasons for staying away from fruit juice before your workout. First, fruit juice is liquid fructose minus the fiber from the fruit, which can overwhelm the liver and cause a rapid rise in blood sugar, causing a blood-sugar crash,” Zembroski says. And the second reason? The liquid fructose will reach your small and large intestines really quickly, causing quick fermentation and an influx of water in the colon, which could cause bloating and diarrhea.
Steak is a major source of protein—just not one you want before a workout. Especially because, according to Cady, it can take 24 to 36 hours for your body to fully digest. Yikes. “That means your dinner is still sitting in your stomach the next morning, making your workouts feel a bit sluggish,” she explains. “If you’re gearing up for a killer a.m. bootcamp class or running a race the next day, avoid steak the night before. You want your body focused on your workout, not on digesting last night’s dinner.”
Broccoli is nothing less than a health-boosting superstar. The veggie helps prevent cancer, fight off inflammation, and even reduces cholesterol. The only issue is if you want to reap all the benefits, you have to schedule your broc-packed meal after your workout. Cady says like cauliflower and kale, the cruciferous vegetable can cause all sorts of discomfort since your body can’t digest it properly while you’re sweating it out.
If you’re a fan of morning workouts, avoid eating your favorite yogurt breakfast beforehand. Even though it’s a healthy way to start the day, Zembroski says it’s best to wait until after your sweat sesh to get your fix: Like milk and cheese, it contains lactose, which could cause bloating, gas, and diarrhea.
19. Spicy Foods
Any other time, spicy foods are a plus, increasing your metabolism and helping you burn an extra 116 calories per day. If you eat something hot before your workout, though, you’re certainly going to regret it. According to the Mayo Clinic, they can cause a serious case of indigestion and heartburn, making it tough to get through your typical routine pain-free.
Any bubbly drink pre-workout is a major no-no—probiotic-packed kombucha included. “Just like sparkling water, the natural carbonation in kombucha can lead to some weird burps if you chug this gut-friendly fermented beverage and then go for a run,” Cady says. “Instead, simply sip on water before your workout to properly hydrate—and save your kombucha as a reward for after you’ve finished your sit-ups and burpees.”