A Gut Health Expert Offers Solutions to Common GI Issues

Molly Hurford
by Molly Hurford
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A Gut Health Expert Offers Solutions to Common GI Issues

Do you occasionally find yourself on a long run when you start to notice a gurgle coming from your gut? Or what about that pre-race sprint — not for a warmup, but to the port-a-potty? While running is an amazingly fun and rewarding sport, it’s not without the occasional downside, including digestive troubles. The good news for runners: Much of the science conducted around athlete gut health involves runners. The bad news: That’s largely because we’re so prone to potential gut issues on the run!

Gut issues are more common than you might think, so there’s no need to panic when those gurgles happen, says Patrick Wilson, PhD, author of  “The Athlete’s Gut.” He says that based on surveys and studies, most runners deal with at least one or two gut disturbances (ranging in severity from a minor cramp to a major bout of diarrhea) over the course of a month of training. There are plenty of reasons — from food intolerances to time of day to stress.

Here’s how a gut-health expert would tackle a few of the most common stomach symptoms that runners face.


Of all the symptoms runners complain of, nausea has the most root causes, Wilson explains. “Anything that really triggers the nausea center in your brain can be a source,” he says. That includes stress hormones like catecholamine and adrenaline, which are more likely the cause when dealing with runners reporting nausea during races, intense sprints or hard tempo workouts.

In those cases, slowing down is the obvious solution, but if you don’t want to drop your pace, you can do other things, like skipping the pre-workout coffee and avoiding caffeine. If you’re doing a workout fasted, that could also cause nausea, he adds, especially if a runner sips a morning espresso and runs on an empty stomach. In that case, he recommends opting for decaf and eating a light meal pre-workout, skipping any high-fat foods.

Lastly, heat stress might be causing your guts to feel curdled, so ensure you have cold water to sip on hand, and even consider moving your run time to cooler points of the day.

“Nausea is not the most common symptom, though, if you’re experiencing it on a weekly basis, or even once every couple of weeks during runs, that raises more of a red flag than if it’s a once-a-month issue, and you may want to check in with a doctor,” he adds.


“There’s even a nickname for diarrhea specific to runners because it’s such a common issue: runner’s trots,” Wilson says. “Again, there are multiple potential causes.” The most prominent cause he sees is stress and anxiety outside of running or brought on by the stress of an upcoming race (hence the long port-a-potty lines at a race start). “Because an athlete is stressed or anxious, that tends to have the effect of increasing motility in the lower part of the gut, which can propel anything in it out.” Wilson is a fan of treating this naturally, by developing a meditation or mindfulness practice and doing some deep breathing.

But, as with nausea, caffeine can also exacerbate the situation, so skipping the pre-run latte should help. Another option is to space your meals farther out from your run: “There’s something called gastro-colic reflex, where after you eat something, your stomach communicates with the lower half of your gut to say, ‘We’ve got food coming in. We’ve got to make room for this eventually.’ So there’s this kind of reflex that kicks in and, and it’s more likely for you to have a bowel movement within 30–60 minutes of eating.”

Wilson adds he doesn’t recommend anti-diarrheal medication as a rule. “Definitely don’t go overboard with it,” he says. Occasionally, it’s fine, but it shouldn’t be a requirement to get through a run.



That feeling of being overstuffed, a painful sense of fullness or even distention of the stomach is common among runners, especially ones who are going long. “I define it as a buildup of gas in the gut that causes an uncomfortable feeling,” says Wilson. “You might feel distended and like there’s something in your stomach, whether it’s gas or something else.” He notes that women more commonly report feelings of bloating, largely due to monthly hormonal fluctuations, but also because the transit time for food in women tends to be slower. “For females who are eating complex carbohydrates and fiber, that is staying in the colon longer, which means it has more time to get fermented and turned into gas. So that’s perhaps one reason why you see bloating being more commonly reported in women, as well as constipation.

His recommendation, in addition to backing off of high-fiber foods for at least a couple of hours pre-run, is to skip carbonated beverages. If bloating is an issue on nearly every run and you’re struggling to find relief, he notes that working with a registered dietitian to try a low-FODMAPS diet (a diet low in a specific type of carbohydrate known to cause stomach issues in some people) might be worth trying.


“The harder the workout, the more it messes with your esophageal function, which can lead to that feeling of acid reflux,” says Wilson. Expect this to happen when you’re working hard, during a workout or sprinting in a race. Luckily, timing your food can be a big help here. “Avoid eating a big amount of food 30–60 minutes before a workout. Give yourself more time between working out and eating, and when you have that pre-workout meal, skip fatty foods, caffeine and even carbonated beverages, since they can provoke that reflux response.”

But it might be partially in your head as well: “One last thing I would mention is the psychological side,” says Wilson. “There’s some interesting research where they’ve taken individuals and stressed them acutely in a laboratory setting. What they’ve seen is that when you stress somebody, even if the same physical stimuli is used to create a feeling of acid reflux, they rate that reflux as worse. So we’re learning that when people are stressed or anxious, a lot of times they get more hypersensitive to their environment. If you’re stressed about something, you may be more sensitive to what you’re consuming and how you’re reacting to it.”

Whether you want to run your first mile or set a PR, having a plan gets you there faster. Go to the MapMyRun app, tap “Training Plans” and set your next goal — you’ll get a schedule and coaching tips to help you crush it.

About the Author

Molly Hurford
Molly Hurford

Molly is an outdoor adventurer and professional nomad obsessed with all things running, nutrition, cycling and movement-related. When not outside, she’s writing and podcasting about being outside, training and health. You can follow along with her adventures on Instagram at @mollyjhurford.


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