Extreme exercise could poison you

Researchers have discovered that extreme exercise can cause intestinal bacteria to leak into the bloodstream, leading to blood poisoning.

According to the researchers from Monash University in Australia, anything over four hours of exercise and repetitive days of endurance exercise is considered extreme.

“Exercising in this way is no longer unusual — waiting lists for marathons, Ironman triathlon events and ultra-marathons are the norm and they’re growing in popularity,” said Ricardo Costa, the lead researcher.

“It’s crucial that anyone who signs up to an event, gets a health check first and builds a slow and steady training programme, rather than jumping straight into a marathon, for example, with only a month’s training,” he added.

The research team found that people who were fitter and trained over a longer period of time leading into the ultra-marathon event had higher levels of Interleukin 10 — an anti-inflammatory agent that allowed them to damp down negative immune responses.

“The body has the ability to adapt and put a brake on negative immune responses triggered by extreme endurance events. But if you haven’t done the training and you’re unfit — these are the people who can get into trouble,” Dr Costa said.

SYSTEMIC INFLAMMATORY RESPONSE

The researchers monitored people participating in a range of extreme endurance events, including 24-hour ultra-marathons and multistage ultra-marathons, run on consecutive days.

The findings, published in the International Journal of Sports Medicine, show that blood samples taken before and after the events, compared with a control group, proved that exercise over a prolonged period of time causes the gut wall to change, allowing the naturally present bacteria, known as endotoxins, in the gut to leak into the bloodstream.

This then triggers a systemic inflammatory response from the body’s immune cells, similar to a serious infection episode.

The study is the first to identify a link between extreme endurance exercise and the stress it may place on gut integrity.

“Nearly all of the participants in our study had blood markers identical to patients admitted to hospital with sepsis. That’s because the bacterial endotoxins that leach into the blood as a result of extreme exercise, trigger the body’s immune cells into action,” said Dr Costa.

This article was first published in the East African .