RUNNER’S HEART VS. SWIMMER’S HEART
We all know that any aerobic exercise has a beneficial effect on the heart. It becomes larger, stronger, and more efficient. The left ventricle changes the most. It receives oxygen-rich blood from the lungs and pumps it to the rest of the body.
Researchers in Canada set out to see if heart function was different in swimmers when compared to runners. Sixteen world-class swimmers and sixteen world-class runners were studied. Both men and women were in the study and some runners were sprinters, while others were distance specialists. Elite athletes were selected, because they had years of strenuous training, and this provided enough time for cardiac changes to occur.
While at rest, each person was studied in detail with an echocardiogram, which revealed all the hearts to be larger than that of the average sedentary person. The average heart rate, among the two groups, was a low 50 beats per minute, with the runners having a slightly slower rate. In all normal heart activity, the left ventricle contracts with a strenuous twisting and then unspooling motion. This action is similar to a sponge being wrung out and springing back to shape. It was this twisting motion, along with the filling time, that was of most interest to the researchers.
Although the differences between the two groups were slight, they were significant. The runners’ hearts filled a little faster than the swimmers’ hearts and also untwisted more quickly during each heartbeat. The scientists believed the differences most likely relate to the fact that, unlike runners, the swimmers are in a prone position where they do not have to fight gravity. Blood flows more easily when the body is prone than when it is vertical.
This study shows that the body is incredibly and wonderfully able to change its anatomy and function to meet the demands placed on it. It changes, but only as much as necessary. It seems that the runners’ hearts had to undergo more extensive change because of the demand placed on them by gravity. The researchers suggested that swimmers might benefit from adding some running to their routine. The study does not imply that one form of exercise produces a better heart than the other since all hearts were extremely strong and well-suited to their sport and healthy living. It is likely that other sports also sculpt the heart in ways necessary for peak performance.
It is a miracle that the body is exquisitely sensitive to the demands placed on it and can adapt to almost anything. Just give it the right exercise routine, and enough time, and let the magic happen.