Too much exercise can cause acute, chronic GI issues
As exercise intensity and duration increases, so do markers of impaired gut integrity and function, which could lead to a condition investigators called exercise-induced gastrointestinal syndrome.
“Specifically, the cells of the intestine are injured and the gut becomes more leaky, allowing pathogenic endotoxins normally present and isolated to the intestine to pass into the bloodstream,” which could lead to acute or chronic health issues, according to a press release.
“Despite excessive exercise being confirmed to compromise gut integrity and function, we have identified several exacerbating factors which can be controlled, and several prevention and management strategies that can attenuate and abolish the damage and compromised function,” Ricardo J. S. Costa, PhD, RD, of Monash University in Australia, said in the press release. “It is recommended that a full gut assessment during exercise should be undertaken by individuals with symptoms of gut disturbances during exercise, to ascertain what is causing the issue and to develop individually tailored management strategies.”
Costa and colleagues reviewed relevant medical literature published during the last 20 years to evaluate the impact of acute exercise on markers of GI integrity and function in both healthy individuals and in patients with existing GI conditions.
They found “considerable evidence” that increased exercise intensity and duration are proportionally linked to increases in markers of intestinal injury, permeability and endotoxemia, as well as impaired gastric emptying, slower small intestinal transit and malabsorption. Running and exercising in hot temperatures appeared to exacerbate these markers.
Notably, the researchers concluded that significant GI disturbances appeared to emerge at an exercise stress threshold of at least 2 hours at 60% VO2max, regardless of an individual’s fitness.
Finally, they found that low to moderate exercise may benefit patients with inflammatory bowel disease or with functional GI disorders like irritable bowel syndrome, and while data on the health effects of more strenuous exercise in these patients are scarce, it “is likely to be detrimental,” according to the press release.
“Whether [exercise-induced gastrointestinal syndrome] is associated with the development of chronic disease acutely or after repeated insults remains unclear, but is of concern and requires more research,” Costa and colleagues wrote. – by Adam Leitenberger
Disclosures: One researcher (Gibson) reports financial relationships with AbbVie, Ferring, Janssen, Merck, Nestle Health Science, Danone, Allergan, Pfizer, Celltrion, Takeda, Fresenius Kabi, Mylan, Falk Pharma, and A2 Milk Company. He also reports his department financially benefits from the sales of a digital application and booklets on the low FODMAP diet, and he has published an educational/recipe book on diet.