Rowing has long been heralded as one of the most physically demanding and physiologically beneficial sports.
With its intense aerobic demand and full-body coordination, rowing builds cardiovascular strength, endurance and resilience like few other disciplines.
It’s also a sport that attracts driven individuals who thrive on high performance and longevity, often training with unwavering dedication well into their later years.
But as researchers look more closely at the effects of lifelong endurance training, new findings are reshaping our understanding of the athlete’s heart, and the unique rhythms that come with it.
Rower's hearts provide a unique insight
Dr Andre La Gerche, a world-leading sports cardiologist and former endurance athlete, has spent his career studying how intense training impacts cardiac health.
“I probably would have been a sports star if I could,” Dr La Gerche said. “But I wasn’t any good. So I started studying my friends and those small studies led to bigger studies.
"I’m still intrigued, at whatever age I am, by how the heart works during intense exercise. It’s a bit of a miracle.”
His fascination with the athlete’s heart led him to rowing, a sport that not only produces some of the highest VO₂ max readings across all disciplines but also features athletes with some of the largest and most powerful hearts.
“Rowers really are the biggest engines,” Dr La Gerche said.
“Their heart size is related to both fitness and body size, and rowing demands a unique combination of both. Plus, the training diaries of elite rowers are among the most intense we’ve seen, on and off the water.”
Rowing’s physiological demands make it a perfect model for understanding both the benefits and potential side effects of endurance training.
Landmark study reveals new data on AF
One area of interest that has gained increasing attention is atrial fibrillation, or AF, a type of heart rhythm condition that, while not life-threatening, is common in older populations and has now been identified more frequently in athletes.
Dr La Gerche recently co-authored a landmark study that investigated the prevalence of AF among former elite Australian rowers.
The findings were clear and unexpected.
Among the 121 former athletes aged between 45 and 80, one in five were found to have AF.
That’s a prevalence rate almost seven times higher than their counterparts in the general population.
“We knew it was more common in endurance athletes,” Dr La Gerche said, “But what surprised us was just how common it was.”
AF occurs when the upper chambers of the heart, called the atria, begin to fire erratically, disrupting the heart’s normal rhythm.
Instead of a steady metronome-like beat, the rhythm becomes chaotic, often described as “irregularly irregular”.
Some people feel it as palpitations or a fluttering in the chest. Others might experience breathlessness or fatigue during exercise.
And surprisingly, some people don’t feel anything at all.
“It’s really important to know if someone has AF, even if they don’t feel it,” Dr La Gerche said.
“Because even in the absence of symptoms, it can increase the risk of stroke. Especially if you’re older or have other risk factors like high blood pressure.”
Genetics can play a part
While the study showed that both body size and endurance training contributed to increased risk, the research also uncovered a genetic component.
“It’s not so much that there’s one ‘AF gene,’” Dr La Gerche said. It’s a polygenic risk, lots of little gene variations that combine to increase your chances.”
Interestingly, while the genetic risk was the same in athletes and non-athletes, the rowing population showed a much higher prevalence of AF.
The implication is clear: in athletes with a high genetic predisposition, the physiological adaptations to training, like atrial enlargement, can amplify the risk.
Yet, despite the statistics, the key message from Dr La Gerche is one of awareness, not alarm.
AF is not a reason to stop rowing or training.
“It’s never associated with sudden cardiac death. It’s not a life-threatening condition,” Dr La Gerche said.
“In fact, we treat it much like we would treat tennis elbow. You don’t tell someone to stop playing tennis because of tennis elbow, you manage the issue so they can keep playing. We do the same with AF.”
In practice, this means tailoring treatment to the individual.
Some people may require blood thinners to reduce the risk of stroke. Others might benefit from rhythm or rate control medications.
In all cases, the aim is to keep the athlete doing what they love: rowing.
Interestingly, even among athletes who stopped training decades ago, AF rates remained elevated.
This suggests that while ongoing training might not directly cause AF, the cumulative effect of high-level training earlier in life has lasting structural impacts on the heart.
“We saw similar rates of AF in athletes who continued training and those who retired. So, stopping training may not necessarily lower your risk. That said, it also means there’s no reason to stop training unless the AF is interfering with your performance or comfort.”
New global study to paint a clearer picture
To better understand these long-term effects, Dr La Gerche is leading the Prospective Athlete Heart Study, a global research project that is following endurance athletes aged 16 to 24 over decades.
The aim is to gather detailed cardiac data early in an athlete’s career and track how their hearts evolve.
Participants undergo a VO₂ max test, an echocardiogram, a 24-hour Holter monitor, a blood test, an ECG and a state-of-the-art MRI that images the heart in motion during exercise.
These results provide a ‘cardiovascular passport’ of sorts, a baseline that can be used for comparison later in life.
“The reason we’re doing this is to remove bias. If you study only the athletes who are still competing at 40, you miss all the ones who dropped out due to symptoms,” Dr La Gerche said.
“By starting at the beginning of their careers, we capture everyone; those who thrive, and those who might struggle. And that’s how we can start to identify early warning signs.”
The results from this study could inform future recommendations around training loads, screening and athlete monitoring.
Already, the research team has seen potential signs, like unusually low peak heart rates, that could indicate overtraining.
And with nearly 500 athletes already enrolled across Australia and Europe, including Tour de France stage winners and elite rowers, the data will offer insights not just for high-performance athletes, but for everyday Australians as well.
Balance the key as exercise remains vital
Ultimately, Dr La Gerche’s message to the rowing community is one of balance and partnership.
Exercise remains one of the most powerful tools for long-term health, and the benefits of rowing far outweigh the risks. But like any powerful tool, it requires understanding.
“Our goal is to make sport as safe and healthy as it can be. If we can identify the small number of people who may have issues, and help them manage those issues early, then we can keep everyone on the water, doing what they love, for as long as possible.”
Rowers, coaches and families who want to learn more about AF and Rowing Australia's approach to cardiac health are encouraged to explore the latest resources.
These include detailed information on atrial fibrillation and how to participate in the ongoing research.
To read more or express interest in the Prospective Athlete Heart Study, visit: https://www.proatheart.be/en/pro-heart-the-prospective-athletes-heart-study/