Strong exercise for more than two hours at a time can lead to bowel problems, according to a new study.
Excessive exercise can cause damage to bowel cells, creating short-term and long-term digestive problems, as a team of Australian scientists says. Health complications may then occur as toxic substances leak through the injured gastrointestinal wall into the bloodstream, the researchers said.
The research, published in the journal Alimentary Pharmacology & Therapeutics, showed that these effects may be aggravated by running or other forms of exercise at high temperatures. Two or more hours of exercise at 60% of the maximum intensity of a person was the limit in which gut problems occurred, "regardless of the fitness level," the study said.
"While there is evidence of health benefits from moderate exercise in patients with inflammatory bowel disease or functional gastrointestinal disturbances, the safety of more intense exercise has not been proven," scientists say. Dr. Ricardo Costa, the lead author, said the study - a review of existing studies over the past 20 years - has confirmed that excessive exercise can "undermine intestinal integrity and bowel
He added, however, that he and his team "have identified several factors that can be controlled several prevention and management strategies that can reduce or even eliminate the damage and help the bowel function."
"It is recommended that the intestine is fully evaluated during exercise in individuals with symptoms of bowel disorders during exercise to ascertain what is causing the problem and to develop management strategies tailored to the individual's needs."
Sports, in which a high percentage of participants reported gastrointestinal symptoms such as nausea, stomach upset, heartburn and cramps, is the hyperbaton, where 96% of runners suffered from bowel and triathlete problems, with 93% of athletes showing similar annoyances.