My! What Big Ventricles You Have!

When you hit the pavement for a run, you are most likely not thinking about changing the way your heart looks. Instead, exercisers are often focused on building endurance, six-pack abs or achieving an all-over slim down.

But new research shows that, in addition to long and lean legs, exercise can also cause structural changes in the heart. The changes vary, however, according to the type of training in which an athlete is engaged.

In the study, researchers discovered that endurance athletes showed an increase in the size of both their left and right ventricles after 90 days of training, while athletes who only did strength training had too much growth in their left ventricles, but a difference was not seen in their right ventricle size. What’s more, the ability of the left ventricle to completely relax between beats was enhanced in the endurance athletes, but it only got worse in the strength trainers.

Researchers have not yet determined whether it is exercise that changes the structure of the heart or whether it is more likely individuals with abnormally large left ventricles are more likely to become athletes.

Investigators say the findings go against the notion that people are capable of becoming competitive as a result of their heart structures, and instead prove that it is athletic training that is largely responsible for so-called "athlete's heart.” [MSNBC]