Is Your Workout Messing with Your Gut?

You know that a heart-pumping workout is good for your body and mind. But if your sweat sesh leaves you with an upset stomach or running from the streets to the bathroom, it might not be so coincidental. According to new research published in Alimentary Pharmacology & Therapeutics, intense exercise may actually make you more prone to gut damage.

Exercise and Gut Health: The New Science

Researchers from Monash University in Australia set out to review research on exercise-induced gastrointestinal syndrome, published over the last 20 years. They wanted to determine if — and how — exercise impacts digestive health and function.

What they found: As exercise duration and intensity increased, so did the risk of damage to the GI tract. So not only does the stress of exercise slow digestion and make you feel bloated or nauseous, it can also make your gut more leaky. Though experts are still investigating leaky gut syndrome, it’s said to allow bad bacteria to escape out of the gut and into the bloodstream, which can cause a variety of health problems.

While low-to-moderate physical activity may help with a healthy microbiome (especially for those with irritable bowel syndrome or inflammatory bowel disease), there’s a line between the beneficial and the not-so-beneficial. In fact, researchers found a tipping point where things start to go amiss.

When Exercise Starts to Harm Gut Health

“Two hours at 60 percent VO2 max, or the equivalent, is the point whereby all aspects of gut disturbance is consistently significant,” says Ricardo Costa, PhD, lead author of the review. And it doesn’t matter if you’re an elite athlete or training for your first marathon. “Fitness status is irrelevant. Fitter athletes can push themselves harder and create more damage,” he says. Running or exercising in temperatures higher than 86 degrees Fahrenheit doesn’t help either. Both could make the symptoms worse.

So what’s an endurance junkie to do? The study’s recommendations include properly hydrating before and during exercise, as well as avoiding certain medications like non-steroidal anti-inflammatory drugs (NSAIDs), which can irritate your belly. Since the effects of exercise on digestive health can vary by person, Costa also advises an individual assessment. “A gut challenge assessment during exercise is advised to determine the extent of individual gut perturbations,” says Costa. “This will also advise feeding strategies during exercise,” which may help protect against symptoms.

While the study serves up some compelling links between exercise and digestive health, further research is needed to determine the best strategies for preventing and managing exercise-induced gastrointestinal syndrome. So don’t stop signing up for those fall races. Your body will still benefit.