The health and fitness benefits of endurance training are too numerous to mention in just one paragraph, however researchers working in Australia at the University of Melbourne’s St. Vincent Hospital have found that hard endurance training for such sports as marathon running and triathlon pose a risk of heart damage.
Specifically, "Marathon runners and others engaging in extreme endurance exercise may temporarily damage the right ventricle of their hearts, researchers found," according to Bloomberg News.
The researchers followed 40 endurance athletes.
The good news?
The heart damage was temporary in all but a handful of the 40 endurance athletes that were studied. However 5 of the athletes showed more lasting damage the researchers found.
“The heart rebuilds in a manner such that it is more capable of sustaining similar exercise stimulus in the future,” said lead scientist Andre in a statement. “The question is whether there are some athletes in whom extreme exercise may cause injury from which the heart does not recover completely.”
Bloomberg goes on to report that, "The study participants trained for more than 10 hours a week and had no known heart problems. They agreed to undergo magnetic resonance imaging, blood tests and echocardiography a few weeks before the race, immediately after the event and 6 to 11 days later.
Right after the race, the athletes’ hearts had changed shape, with volume increasing and the function of the ventricle decreasing, the study found. The five athletes whose hearts hadn’t fully recovered in the last test showed signs of scarring known as fibrosis, and they had been training and competing for longer than the others, the researchers said.
The findings shouldn’t be seen as an indication that endurance exercise is unhealthy, the researchers wrote."