Scientists say that running marathons may cause permanent heart damage, the Daily Mail reported.
A recent study found that high-endurance activities can result in scarring of the right ventricle and in turn increase the risk of heart complications.
The study examined 40 elite athletes with no history of heart problems who were planning to compete in an upcoming endurance event, like a marathon.
Test results showed that immediately after racing, the athletes’ hearts had changed shape and grown in volume, while the right ventricle function decreased.
“Our study identifies the right ventricle as being most susceptible to exercise-induced injury and suggests that the right ventricle should be a focus of attention as we try to determine the clinical significance of these results,” said lead researcher Dr. Andre La Gerche, from the University of Melbourne, Australia.
“Affected athletes may be at risk of reduced performance – a cardiac 'over-training' syndrome – or it may cause arrhythmia (erratic heart beats),” he added.
Ventricle function recovered in most of the athletes after a week, but in five of the athletes there were signs of potentially permanent scarring.
“My personal feeling is that extreme endurance exercise probably does cause damage to the heart in some athletes,” La Gerche said. “I don't believe that the human body is designed to exercise at full stretch for as long as 11 hours a day, so damage to the heart is not implausible.”
The researchers said they hope the discovery will lead to treatments and possible preventative measures, but in the meantime they are urging runners to use sensible training techniques and to give their bodies adequate time to recover after marathons.