Olympic hearts in good shape despite hard training

Competitors jump during the men's quarterfinals run for the BMX cycling competition at the Beijing 2008 Olympic Games August 20, 2008.

NEW YORK (Reuters Health) - Hard endurance training is unlikely to cause lasting heart problems, a study of Olympic athletes from Italy suggests.

The findings ease concerns that had arisen after doctors found that some cyclists in the Tour de France had enlarged, but weakened hearts. Whether this was due to excessive physical training or steroid use, however, was unclear.

To test how prolonged and intense exercise affects the heart, Italian researchers studied a group of 114 young national athletes who had trained for several years and participated in at least two Olympic Games. The athletes included rowers, cross-country skiers, runners, and cyclists, among others.

At two separate examinations, spaced about eight years apart, the researchers found no change in how much blood the athletes' hearts pumped into their bodies during exercise. Their heart muscle also looked the same overall, although a part of it had expanded slightly.

According to the researchers, who reported their results in the Journal of the American College of Cardiology, the results suggest that even hard training doesn't put a healthy heart at risk, even if it increases its size -- a phenomenon aptly known as athlete's heart.

It also means that the earlier findings in cyclists are likely to be due to performance-enhancing drugs such as erythropoietin, or EPO, which boosts red blood cells.

"An athlete's heart is a good heart," said Dr. Malissa J. Wood of Massachusetts General Hospital in Boston, who was not involved in the new study. "It's healthy and it allows the athlete to train at a higher intensity."

"This is an important study giving more evidence as to why exercise is good for you," she added.

SOURCE: Journal of the American College of Cardiology, 2010.