You’re ready for a group run or HIIT class and before you’re two minutes into it, you’re stomach’s rumbling, cramping and swelling. There are many weird side effects of working out and gastrointestinal issues are definitely part of them—some of the more embarrassing ones at that. (You’ve surely heard that Chris Weidman admitted to nearly soiling himself in The Octagon at UFC 187.)
So if burpees make you burp and running, well, gives you the runs, heed to this advice from Marni Sumbal—a dietician who specializes in sport nutrition for triathletes and runners—on preventing the most common stomach issues during a workout. Sumbal herself is a 9x Ironman finisher, so it’s safe to say she’s had some experience battling belly bloat and indigestion during training or a race. With her easy diet and lifestyle hacks, you can be on your way to a happier stomach and an overall more enjoyable workout experience for years to come.
To avoid stomach discomfort and gas, you really need to limit high-fiber foods within four hours of exercise. You don’t want to be sprinting or squatting as you’re digesting (and no one wants to be behind or near you either). “Before a workout, eat low-fiber foods that require minimal digestion like a rice cake or applesauce instead of a piece of bread or an apple,” Sumbal says. Sweeteners and alcohols—found in most protein bars and low-cal sport drinks—can also worsen the problem. If you’re still confused, check out our best pre-workout foods.
Bloating can be caused by a variety of things. You’re binging on junk food, consuming too much dairy, or just simply overeating (among others). To avoid the discomfort, follow these two guidelines: “If you’re eating a pre-workout snack of about 100-200 calories, give your body at least one hour to digest,” Sumbal says. “If you’re consuming a pre-workout meal of about 300 calories or more, allow at least three to four hours to digest.” You don’t want to look and feel like you have a beer belly, so stop the bad pre-workout habit—today.
Don’t go into meals starving—you’re more likely to overeat, which is one of the main causes of indigestion (burning in your upper abdomen, bloating, nausea)—and avoid highly acidic foods like tomato sauce, citrus fruits, coffee, and soda before a workout to decrease stomach upset.
“Although a low-fiber or low-fat snack around 60-90 minutes before a workout may minimize symptoms, some individuals may need to wait two hours for food to fully digest before working out,” Sumbal says. “And if you can’t avoid working out within two hours of eating, limit exercises that may cause abdominal pressure or require your body to move in different planes of motion, which could aggravate the stomach (ex. yoga, CrossFit),” Sumbal adds.
Note: If dietary modifications don’t minimize your symptoms, discuss with your doctor about a possible gastrointestinal issue.
4. Heartburn/acid reflux
Like indigestion, heartburn and acid reflux can be caused and aggravated by the types of food you’re eating and exercises you’re performing. “Limit exercises that require lying down (ex. crunches) within the first 20-30 minutes of your workout,” Sumbal advises. Start with a light warmup to get your blood flowing and body primed instead. You should also avoid spicy and fried foods to minimize reflux, and stay hydrated throughout the day. In short, use common sense; pay attention to the foods that cause your stomach irritation and make note not to eat them again.
Hydration is key—you’ve heard this before and you’ll hear it again. If you’re dehydrated during a workout, you may feel lightheaded, weak and your stomach will probably cramp up if you’re doing cardio. Two to three hours before a workout, Sumbal says to drink 14-22 oz of water, plus an additional 8-10 oz 30 minutes before you begin. She also says to ease into your workout routine. Oftentimes cramps form if you’re working out too hard too soon into a routine.
It’s easy to confuse nausea with low blood sugar or blood pressure issues. (Note: It’s important to consult with your physician if you feel any recurring health issues when working out.) The best way to combat this is to strike the right balance food-wise. You don’t want to eat too much or too little before a workout. “Twenty minutes beforehand, have a glass of juice, a box of raisins or a small banana,” Sumbal suggests. “Or an hour before, have a banana with a smear of nut butter and a drizzle of honey.” You want to be satiated, fueled and ready—especially if you have a gruelling workout planned. You don’t want to be overstuffed or running on empty.
7. Urge to go to the bathroom
Our biological needs have a funny way of ruining workouts. A good rule of thumb if you always have to go to the bathroom in the first 30 minutes of any workout, is to use that time as a warmup. Read: Stay close to a restroom. “Most individuals need a warmup to get their systems going and that means your gastrointestinal system as well,” Sumbal says.
If you’re overcome by the urge to pee every time you make it a quarter of a mile into your run, you may be overhydrating. Drink no more than 22 oz of water two hours before a workout, Sumbal says. If you’re someone who’s constantly plagued by diarrhea or loose stools (it happens to the best of us), consider reducing the fiber and fat in your diet in the two to four hours before a workout and 24-hours before a race. And if you find yourself getting backed up or constipated from time to time, caffeine and water may help to limit pre-workout discomfort and flush out your system, she adds.