SCIENTISTS have warned that the fashion for ultramarathons, triathlons and extreme endurance bicycle races could be putting competitors' lives at risk.
The extreme events are increasingly favoured by celebrities including the comedian Eddie Izzard, who last month halted a bid to run 27 marathons in 27 days in South Africa.
But while moderate exercise is of benefit, participants in extreme sports could risk doing long term damage to their hearts according to a study. Beyond an hour a day, vigorous exercise yields diminishing returns.
The warnings follow the death of Micah True, a US ultra-marathoner, who ran as far as 100 miles in a day. Mr True was found dead of a heart attack in March while on a 12-mile training run in New Mexico.
He was 58.
James O'Keefe of St Luke's Hospital, Kansas, said Mr True may have died of cardiomyopathy, a thickening of the heart muscle which caused it to beat irregularly or pump inadequately, brought on by excessive exercise. (© Independent News Service)