High-endurance activities can lead to scarring of the right ventricle, increasing the risk of health complications.
Researchers hope the discovery will prompt the development of suitable treatments and preventative measures, Daily Mail reported Wednesday.
They are urging elite athletes to adopt sensible training techniques and allow adequate recovery time after events.
Lead researcher Andre La Gerche, from the University of Melbourne, Australia, said: “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.”
Scientists assessed 40 elite athletes with no history of heart problems who were planning to compete in one of four endurance events.
Test results showed that immediately after racing the athletes’ hearts had changed shape, growing in volume, while right ventricle function decreased.
After a week right ventricle function recovered in most, but in five there was evidence of potentially permanent scarring.
The right ventricle is one of the heart’s four chambers and pumps blood to the lungs. Scar tissue can weaken over time and can form an abnormal bulge of tissue known as an aneurysm.
In conjunction with other heart problems this mass can cause the heart to enlarge, reducing its ability to pump blood effectively, resulting in heart failure, the Mail added.
Professor Sanjay Sharma, of St George’s University London and medical director of the London Marathon, called for more research looking at larger groups of endurance athletes.