SmarterFitter

A recent Harvard study has found that 90 days of athletic training not only produces significant changes in the heart, but those changes vary with the type of exercise performed.

Researchers at Massachusetts General Hospital (MGH) followed two groups of Harvard University athletes: one group of endurance athletes, and another group of strength athletes. They used ultrasound technology to study the athlete's hearts before and after the 90-day period. Both groups showed significant increases in the size of their hearts, but the locations of the increase differed:

• Endurance exercise expanded the left and right ventricles, the chambers that send blood into the aorta and to the lungs, respectively, and increased the relaxation of the heart muscle between beats.


• Strength exercise thickened the heart muscle, primarily the left ventricle, and decreased the relaxation of the heart muscle between beats.

Researchers were surprised by both the magnitude of changes over a short time period and by how great the differences were. It also raises questions about the long-term impact of exercise, especially for people with heart disease. Aaron Baggish, MD, lead author of the study, says:

While this study looks at young athletes with healthy hearts, the information it provides may someday benefit heart disease patients. The take-home message is that, just as not all heart disease is equal, not all exercise prescriptions are equal. This should start us thinking about whether we should tailor the type of exercise patients should do to their specific type of heart disease.

How Exercise Changes Structure And Function Of Heart