Scars of Glory: Veteran Endurance Athletes May Risk Their Hearts
Endurance sports are celebrated for their health benefits, but a new study suggests that lifelong intensity may leave an unexpected mark on the heart.
Researchers at the University of Leeds, in collaboration with the British Heart Foundation, found that nearly half of veteran male endurance athletes, aged over 50 and engaged in decades of training, show signs of heart scarring, even though they appear healthy and symptom-free.
The study involved 106 competitive cyclists and triathletes who logged over 10 hours of exercise per week for at least 15 years. Each participant underwent MRI scans to detect myocardial fibrosis and had an implantable loop recorder fitted to monitor heart rhythms over two years.
Over that period, 47% exhibited scarring, typically in the left ventricle, compared to just 11% in a low-exercise control group. Alarmingly, 23 athletes (about 22%) experienced episodes of ventricular tachycardia, a fast heart rhythm often linked to cardiac arrest, and most of those had detectable scarring. Three athletes even had sustained episodes longer than 30 seconds, a potentially life-threatening condition.
“Scar formation in the heart is common in about half of these athletes,” said Professor Steffen Petersen, who reviewed the findings. He noted that the scarring observed was not caused by blocked arteries, but likely due to mechanical stress or inflammation from years of intense training. Some scars were associated with arrhythmia risk, while others appeared benign.
Despite the warnings, researchers emphasize that exercise remains overwhelmingly beneficial for most people. “These were high-intensity, highly trained athletes,” explained Dr Peter Swoboda, lead author of the study. “This isn’t a warning for recreational runners or cyclists, but a signal that extreme longevity sport may come with cardiac trade-offs.”
One of the study’s participants, Brian Cookson OBE, discovered through monitoring that he had experienced dangerous heart rhythms. He received an implantable cardioverter defibrillator (ICD), which he believes “might well have saved my life.” He still cycles regularly, but with added caution.
Known as the VENTOUX study, this research underscores the importance of heart screening for elite athletes, particularly those with symptoms such as dizziness or chest discomfort.
As sports cardiology evolves, the message is clear: the healthiest hearts may still carry the hidden costs of a lifetime chasing endurance.