It is a name synonymous with Australian sporting folklore.
By the time the Oarsome Foursome’s James Tomkins took part in the Beijing Olympic trials in 2008, he had won three Olympic gold medals and was a seven-time world champion.
But on this particular day, he was not feeling himself. As the crew went through their practice pieces, he could barely produce any power.
“I was absolutely knackered,” he said.
“I’ve never been more exhausted in my life, and I could sort of feel like a weird, irregular heartbeat.”
Tomkins was taken to see a cardiologist, who diagnosed him with atrial fibrillation.
Atrial fibrillation (AF) is a common heart rhythm disorder that is associated with increased risk of stroke and heart failure, while the amount of exercise someone undertakes can affect their propensity to develop it.
According to Professor André La Gerche, an expert on the effects of exercise on the heart, there are two types of people most likely to develop AF: “People who do no exercise, and people who do lots of exercise.”
A study by Dr André La Gerche (left) found elite male rowers like James Tomkins (right) were at an increased risk of developing atrial fibrillation. (Supplied: Victor Chang Research Institute)
It is a fact that has puzzled researchers and elite athletes like Tomkins, given the number of benefits exercise has on general health, including lower risk of cardiovascular disease more generally and type 2 diabetes.
So why are some elite athletes at risk of AF, and does that mean there is such a thing as too much exercise?
Elite male rowers seven times more likely to develop AF
Dr La Gerche, head of the Heart Exercise and Research Trials Lab at the Victor Chang Research Institute in Melbourne, recently teamed up with several researchers to answer these questions.
They recruited 121 elite rowers (of which 74 per cent were men) who had performed at the international level, and compared them with a control sample of non-rowers.
James Tomkins (right) won three Olympic gold medals, including the coxless pair with Drew Ginn (left) at Athens in 2004. (Getty Images: Jamie Squire)
While the authors predicted the rowers would have an elevated risk of AF, the results showed elite male rowers were seven times more likely than the average population to develop AF.
It was a result that shocked Dr La Gerche.
“There’s no way I would’ve predicted that,” he said.
“It’s far more than we expected.”
The finding, however, was restricted to men only, with Dr La Gerche arguing this does not mean elite female athletes are not at higher risk of AF.
He explained that rowing was only introduced as an Olympic sport for women in 1976, with his team unable to recruit enough women to draw meaningful conclusions.
Limited research suggests elite female runners and cyclists are also at increased risk of atrial fibrillation, but more research is needed.
The research team were unable to conclude if elite women rowers are also at elevated risk of atrial fibrillation. (Getty Images: Justin Setterfield)
Do genetics or exercise increase athletes’ risk?
Dr La Gerche and his team then turned their attention to why elite male rowers were at such elevated risk of AF.
As he explained, there are both genetic and exercise-related influences on the development of AF.
In this particular study, the research team were able to conclude that it was exercise, not genetic factors, which led to athletes’ increased risk of AF.
“We found that genetic factors explained some of the AF in athletes, but no more so than the general population,” Dr La Gerche said.
“We can now say that atrial fibrillation in athletes is due to a kind of excess exercise.”
However, Dr La Gerche was quick to qualify that he did not want to scare people off exercise.
“I’m pretty biased, because in my clinic I see people who have a lot of medical illness from a lack of exercise,” he said.
Dr La Gerche said he was shocked by the results of his study into elite male rowers and AF. (Supplied: Victor Chang Research Institute)
By contrast, he points to 80-year-old patients who are doing “everything they want to”, like playing golf and riding their bike, adding that “the benefits of exercise are massive”.
Dr La Gerche argued it was more important to exercise “safely”, using the analogy of tennis elbow.
“If you play tennis, you might be more likely to get tennis elbow or a similar injury, but you wouldn’t say don’t play tennis. You’d say play tennis, but here are strategies to avoid getting tennis elbow.”
Moderate exercise reduces risk of atrial fibrillation
Exercise has also been shown to reduce risk of AF, depending on intensity.
While this study showed that vigorous exercise may increase men’s risk of AF, other papers have shown that moderate exercise lowers the risk of AF in men.
Even for those elite athletes who do develop AF, Dr Le Gerche said it was not a “massive problem”, a sentiment Tomkins shared.
“As long as people are aware of the risk, it’s quite manageable,” Tomkins said.
He has now had two episodes of AF, including the one in 2008, and another late last year.
He laughs sheepishly when recalling the circumstances that led to the most recent incident:
What is ‘holiday heart syndrome’?
“I’d been drinking a bit that day, had a bit of a viral load, and drank an iced Margarita, which my specialist said shocked my heart and put me in AF,” Tomkins said.
Alcohol is a well-known risk factor for AF, while Dr La Gerche’s study showed athletes tended to have “extreme” relationships with alcohol, either drinking in excess, or very little.
This has since led to Tomkins committing to reducing his alcohol intake, while he argues it is important for everyone — not just athletes — to drink in moderation.
Should elite rowers be screened for atrial fibrillation?
The results of Dr La Gerche’s study also raise the question of whether elite rowers (or other endurance athletes) should be screened for AF.
Part of the problem with identifying AF is that not everyone who experiences it will feel as awful as Tomkins has.
“Some people will feel terrible, like their heart is bouncing out of their chest, they might feel light-headed or short of breath, but others will have no idea and feel perfectly normal,” Dr La Gerche explained.
“We don’t understand why there is that spectrum [of responses].”
Both groups, however, are at elevated risk of stroke.
“So unfortunately, what we worry about is the person who doesn’t even know they have AF, and their first knowledge of it is having a stroke,” he said.
Dr Le Garche advises anyone at higher risk to consider getting a device such as a smartwatch that can take an ECG and alert you if you are experiencing AF.
A smartwatch with ECG capability can alert you if you are experiencing atrial fibrillation. (Supplied: WHOOP)
He would also support monitoring for vulnerable groups. As an example, he said elite rowers with a genetic predisposition for AF would be the “highest of the highest risk” group.
Finally, their study showed that elite male rowers remained at elevated risk of heart disease, regardless of whether they had continued to exercise vigorously post-retirement.
“So it’s pretty important to think about not just what exercise people are doing now, but what exercise they have done in the past,” Dr La Gerche said.
“The goal of our research is to identify why these people are getting AF, so that we can prevent or identify it early and make exercise safe for everyone.”