Findings from a new study show how endurance training versus strength training can have different effects on the heart muscle and heart function. Researchers evaluated 40 endurance and 24 strength athletes via echocardiography before and after 90 days of team training with their respective training routines. At the end of the study, both groups had experienced an increased mass in the left ventricle. However, endurance athletes showed better diastolic function in their left ventricle, as well as enlargement and more efficient contraction and relaxation in both of the lower chambers of the heart, or atria. The strength group actually had excessive enlargement in the left ventricle muscle and reduced diastolic function. The researchers commented that the results could help to determine the appropriate exercise for people with various heart problems. It also indicates that people aren't likely born with an "athletes" heart as many believe, but rather, itís the training that is mostly responsible.
Source: Journal of Applied Physiology, April 2008.