One in five former elite rowers develops atrial fibrillation, a heart rhythm disorder that can raise stroke risk, despite having fewer traditional risk factors.
A study of 121 retired Australian rowers, including Olympians, found they were nearly seven times more likely to develop atrial fibrillation (AFib) than the general population.
The research was led by the Heart, Exercise and Research Trials (HEART) Laboratory, with support from St Vincent’s Institute of Medical Research and the Victor Chang Cardiac Research Institute.
André La Gerche, head of the HEART Laboratory, said: “This study tells us not to look past the man or woman with the chiselled quads in the doctor’s waiting room.
“Our study proves that AFib is a side effect of endurance exercise, and it can have serious consequences if missed.
“With the new information that this study brings, AFib can be identified early and treated.
“Some of these athletes had no idea they had AFib until we screened them, as it is a disease that can develop without any outward symptoms.”
AFib causes irregular heartbeats that can lead to blood clots, stroke and heart failure.
It often develops without symptoms and is typically linked to conditions such as high blood pressure, obesity and diabetes.
However, the study found that former elite rowers—despite being generally healthier—had significantly higher rates of AFib. Researchers said genetic factors combined with lifelong intensive training may explain the increased risk.
Participants, aged between 45 and 80 and including around 25 per cent women, underwent MRI scans, ECGs and genetic testing.
While elite athletes often develop healthy heart adaptations—such as enlarged heart chambers and slower resting heart rates—the study found that AFib risk persists long after competitive training ends.
Professor Diane Fatkin of the Victor Chang Cardiac Research Institute, who led the genetic analysis with associate professor Eleni Giannoulatou, said the risk extended into retirement.
Professor Fatkin said: “When we followed up on these athletes, we found more cases of AFib had developed.
“This demonstrates that we need to keep a closer eye on their hearts when they retire and for many years after they stop training.”
The researchers said further work is needed to understand how genetic variation influences AFib risk, what triggers episodes, and whether treatment approaches for athletes should differ from standard care.
Professor La Gerche added: “We shouldn’t forget that athletes live healthier lives for longer. This research should not discourage people from sports like rowing.
“Our job is to make sport safe for everyone and this study is an important advance in heart injury prevention.”
