Man runs 250km marathon in heated tent for research on endurance sport

Marathons and triathlons are widely regarded to be healthy trends – but new research suggests endurance training could be potentially lethal for under-trained participants.

Athlete Richard Bowles is tackling a 250 kilometre marathon - which he’s running inside a heated tent, on a treadmill for six hours a day, under the supervision of researchers from Monash University.

Mr Bowles must consume seven-and-a-half thousand calories a day to sustain the extreme exercise challenge.

The researchers are studying the effects of endurance exercise on the body, from the impact on heart rate and hydration to brain and muscle function.

Dr Ricardo Da Costa said if an individual is too under-trained before tackling an extreme fitness challenge, their health is at risk. Dr Da Costa said some challenges, such as marathons or Iron Man events, could cause a gut disturbance that could trigger blood poisoning.

“If it’s too aggressive, it can become fatal and lead to death. Eventually you get a septic shock,” he told 9NEWS.

“Or if someone only has a month of training, once a week an hour, and then suddenly decides I’m going to do an ultra-marathon, if you do that, you’re looking for trouble.”

Dr Da Costa said with training, an athlete can adapt to endurance exercise.