April 23, 2008 -- Could a specific workout routine help tame particular forms of heart disease? A first-of-a-kind study documenting how various forms of exercise affect the heart suggests that in the future doctors may be able to tailor a patient's exercise regimen to his or her specific heart condition.
Researchers with Massachusetts General Hospital and Harvard University Health Services followed 75 student athletes for 90 days during normal team training to see how vigorous athletics affected their heart structure and function.
"Most of what we know about cardiac changes in athletes and other physically active people comes from 'snapshots' taken at one specific point in time," researcher Aaron Baggish, MD, a fellow in the Massachusetts General Hospital cardiology division, says in a news release. "What we did in this ... study was to follow athletes over several months to determine how the training process actually causes change to occur."
Baggish and colleagues divided the students into two groups: Endurance athletes consisting of male and female rowers and strength athletes made up of male football players. Researchers excluded from the study anyone who reported using steroids.
The students followed the normal training plans established by their coaches and trainers. Endurance training involved one- to three-hour sessions of rowing on the water or on gym equipment. Strength training involved weight training and drills designed to improve muscle strength and reaction time. On average, the students trained for 12 hours per week.
The researchers performed echocardiograms on the students at the beginning and end of the study to assess how their hearts adapted to a typical season of competitive athletics. Echocardiograms provide information about how blood flows through the heart, revealing important details about the organ's structure and function.
Exercise and Heart Changes
After the 90-day follow-up period, the researchers noted profound changes in the students' heart structure and function. But the changes varied depending on the type of exercises performed.
Both the right and left ventricles of the endurance athletes expanded, while the heart muscle in the left ventricle tended to thicken (but did not expand) among the strength athletes. The ventricles are the principal pumping chambers of the heart and are responsible for sending blood to the body and to the lungs.