Swimmers have a big heart. Not just because of their love for their teammates, coaches and family. This is meant quite literally. Studies have shown that regular swimming training can lead to a larger volume and a more powerful beat of a swimmer’s heart.
The fact that sport has a positive effect on the cardiovascular system is no secret. After all, our heart is also a muscle that has to work faster and more intensively as a result of the greater stress it exerts on sports and is thereby strengthened.
In the end of the 19th century however, competitive sports were also found to have an effect on heart mass and heart volume. Several training sessions a week or even daily since adolescence result in an enlargement of the organ.
Studies in the 1990s showed that this is particularly noticeable in specific sports. Especially cyclists, rowers, cross-country skiers and of course swimmers have above average trained pumps. A normal heart weighs about 300g. For swimmers on a high competitive level, the mass can be up to 500g, which is already critical. If it gets bigger, physicians say it could be dangerous.
Especially the left ventricle is often disproportionately big. Studies have shown that it can be 75 percent larger in competitive swimmers than in untrained people. For comparison: In other sports such as football or volleyball, the increase is “only” 30 to 50 percent.
Not only volume and mass of a swimmer’s heart are bigger. The heart wall is also formed above average in swimmers. The heart can beat more powerfully and economically, with less beats it is able to pump more blood through our veins than a non-athlete’s heart ever could. Water also plays a special role for swimmers, since it puts more pressure on the body than air. Thus, the blood vessels are more compressed and the blood is pushed towards the chest. As a result, the heart has to work more with each beat and is therefore better trained.
A swimmer’s pulse also rises more slowly due to the nature of the water, which protects their heart. Due to the above-average training of the heart, it must beat less frequently, even in a rested state. It is not uncommon for swimmers to have a pulse of 40 or even less beats per minute while resting.
By the way, if the regular training is stopped, the swimmer's heart slowly develops back to normal size. Often, the athlete's heart is cited as a reason for athletes to gradually reduce their training schedule after their career in competitive sports instead of suddenly stopping to exercise entirely. However, it has actually not been scientifically proven that an abrupt end to heavy work load has negative effects on the heart. It is still advisable to gradually train less in order to adjust things like the eating behavior, the daily rhythm and the metabolism for the life after competitive sports. Finally, you do not have to worry about your swimmer's heart causing problems if you let it rest three or four weeks during a long summer break. It will still be big and powerful when you head back to the pool afterwards.