A Runner’s Heart is:
- Bigger – An endurance athlete’s heart can be up to 50 per cent bigger than a non-athlete’s heart.
- Can pump more blood around the body – The atria, the upper two ‘filling chambers’ where blood arrives in the heart, are enlarged, as are the ventricles, the two lower chambers that pump blood around the body.
- Has more flexible coronary arteries – The vessels that supply blood to the muscles of the heart are able to expand more to allow more blood flow during exercise even when there are some cholesterol deposits. This ability to dilate makes it easier for blood to get around any partial blockages.
- Has wider, more abundant coronary capillaries – The secondary network of vessels that distribute blood to muscles of the heart may be two to three times bigger than normal.
- Has denser plaques in arteries – dense plaques may be less likely to rupture and cause a heart attack. Emerging evidence suggests that plaques in runners, too, may be denser and more stable.