Exercise is good for the heart, but studies have suggested that people who participate in long-term endurance sport could run the risk of 'scarring' the organ over time. In rare cases overworking the heart can lead to an abnormal heart rhythm or even sudden cardiac arrest.
The British Heart Foundation (BHF) said a study involving male athletes aged over 50 found that around half of the participants had developed scarring on their heart to some extent. It is thought this could be caused by their high levels of exercise as during endurance sports like long-distance running and cycling the heart must work even harder to pump blood. However, it is still unclear how scarring has developed.
Experts stress that just because a person may have heart scarring, it doesn't always mean they will then have a cardiac event, and most will experience no symptoms at all. People will only usually discover they have heart scarring when they have an MRI scan, for example when they are suspected of having a heart condition.
