Harvard University Health Services and Massachusetts General Hospital researchers have found that just 90 days of vigorous athletic training produce significant changes in the heart’s structure and function, and that the type of change varies with the type of exercise performed.

Both strength athletes (football players) and endurance athletes (rowers) had significant overall increases in the size of their hearts, but there also were significant functional differences. The relaxation of the heart muscle between beats increased in the endurance athletes but decreased in strength athletes. The left and right ventricles of endurance athletes expanded, while the left ventricle of strength athletes tended to thicken.

The results suggest that exercises done by heart disease patients might need to be tailored to their specific type of heart disease.

Massachusetts General Hospital News Release