Heart attacks of the mega-fit: how safe is extreme sport?

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This was published 6 years ago

Heart attacks of the mega-fit: how safe is extreme sport?

We don’t just go for a jog any more – we train for a marathon, following in the footsteps of the greats. But when top athletes collapse from heart failure, we start to wonder: how safe is this growing culture of extreme sport?

By Konrad Marshall
Updated

At 7am on August 28 last year, just south of Surfers Paradise, a grey SUV veered off a quiet suburban street and clattered through an aluminium fence. The bingle itself was not serious, yet the driver was in serious trouble. Paramedics arrived promptly and performed CPR for an hour, but the husband and father, on his way home from a dawn training session at a local surf club, could not be revived. The man behind the wheel was Dean Mercer, a champion triathlete and winner of everything from the World Oceanman series to the Coolangatta Gold. Still in peak physical shape, Mercer had suffered an acute cardiac arrest.

Only 47 when he died, shocked and disbelieving mates quickly filled the ether with tributes, lionising a competitor of ascetic devotion, one whose capacity to push his body – and live a life structured around training – was legendary. In the coming week, though, amid the confused conversation around his passing, others were less surprised.

Ironman and triathlete Dean Mercer competing in 2005. Mercer died of a heart attack on the Gold Coast last year.

Ironman and triathlete Dean Mercer competing in 2005. Mercer died of a heart attack on the Gold Coast last year.Credit: Getty Images

Local cardiologist Dr Ross Sharpe was one of them. In the Gold Coast Bulletin, Sharpe described the insidious impact of elite endurance sport, speaking of rhythmic disturbances and plaque ruptures and a condition called "athlete's heart". Other medicos shared his views. Dr Ross Walker, a Sydney cardiologist, spoke with the ABC about toxins and inflammatory conditions and the chronic, recurrent damage wrought by feats of extreme exertion.

"I probably feel one of the reasons for this – and it hasn't been absolutely proven but it's quite logical – is that if you push yourself too hard, you're overstretching all the mechanisms in the body," Walker said. Including the heart. "Like anything that's overworked, it eventually gives up."

In Melbourne, however, Australia's foremost expert on exercise and the heart was inside his lab, shaking his head. Dr Andre La Gerche, the leader of sports cardiology at the Baker Heart & Diabetes Institute, tells Good Weekend he has no idea what had happened to Mercer, or what specific factors were at play in his "cardiac event". No one does.

Indeed the Mercer family, still reeling from the abrupt passing of a son, brother, husband and dad – and in no way ready to speak about the tragedy that befell them – have no conclusive answers of their own, even now. Let alone seven months ago. "From the newspapers and TV it was impossible to tell anything," La Gerche says. "But people were making all these wild guesses anyway."

La Gerche is the most active researcher in his field in the country, perhaps the world, but he isn't much of a self-promoter. He has a Twitter account but has only tweeted four times. All were on the same day – a week after Mercer's death.

First, he linked to a story connecting endurance training with heart attacks, along with his appraisal: "Irresponsible and ill-informed." Second, a statement: "Cardiologists should know there is no proven link between endurance sport and sudden death. Research suggests opposite." Next, a complicated line graph, which he annotated: "Athletes live longer. Endurance athletes and gold medallists live the longest. Have faith fellow athletes." And finally, a summation: "Too sad that people are using a tragic event to push unproven agendas. Great man, sad event, no blame!"

La Gerche nods when I bring up his debut tweetstorm. Friends and colleagues had asked him to speak up, to counter the misinformation swirling all around the event. "There were some blissfully naive views circulating," he says, still incredulous. "To push a message that places blame or fault on endurance sport? It's irresponsible on every level."

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Endurance sport has an undeniably compromised reputation. Its best individual exponents are seen as spartan, as specimens, so there is always drama in their demise. Such stories cannot help but stand out.

In 2007, American athlete Ryan Shay, only 28, succumbed to a fatal heart attack just nine kilometres into Olympic marathon trials in New York City. That same year, former Boston Marathon winner Alberto Salazar felt his heart flutter while walking, then collapsed. The 48-year-old lay dead for almost a quarter of an hour before being resuscitated. (Now an elite running coach, his autobiography is titled 14 Minutes: A Running Legend's Life and Death and Life.) Then there is ultra-marathoner Micah True – the mystical protagonist of Christopher McDougall's best-selling book Born to Run – who passed away in 2012. Famous for running with the Tarahumara people of Mexico, who named him "Caballo Blanco" ("White Horse"), True died alone on a trail run through the New Mexico wilderness at the age of 58.

Such deaths now serve as cautionary tales, invariably making us ponder our own recreational limitations. La Gerche, who also has a private practice, says every third patient now asks if it is healthy to run a marathon. "In the 1970s and 1980s it was promoted as the healthiest thing you can do," he says, "and the evidence hasn't shifted much."

Confusion emerges, he says, when people fail to separate public health from individual risk. Let this be clear, La Gerche explains: exercise in all its forms reduces the risk of cardiovascular disease and diabetes, and extends life – but any individual can also have a heart attack. Coronary heart disease is the biggest cause of death in Australia, with about 20,000 per year – one person every 10 minutes. "These two truths are difficult for many to countenance," says La Gerche. "But common things happen commonly."

Cardiologist Andre La Gerche, a marathon runner, is conducting long-term research into endurance sport and heart health.

Cardiologist Andre La Gerche, a marathon runner, is conducting long-term research into endurance sport and heart health.Credit: Damien Pleming

La Gerche, 44, is an athlete. He doesn't have to say so; it's evident in his low body fat, upright gait, tanned skin – even the windblown lift of his chestnut and grey hair. Oh, and the gigantic Garmin GPS on his wrist. The only question is whether he cycles, swims or runs. He flashes a guilty-as-charged grin. His best marathon time is two hours and 29 minutes, not far off the Olympic qualifying standard of two hours, 19 minutes.

"It's funny, in this whole debate you can line up the people who are so pro-exercise that they're almost intolerant of the concept that there could be a problem, and then the people who are almost fear-mongering," he says. "What I often say is that the only person who is wrong is the person who is sure they're right."

Much of his research raises unresolved questions about endurance sport. In 2008, for instance, La Gerche conducted ultrasounds on triathletes following a race. It was the first study that showed scarring of the heart as a result of endurance sport.

"The hearts actually looked quite sick," he says. "Then they rebounded quickly – within days they looked healthy again – but it gives you pause. I'm sure there would be some scarring in my heart."

By scarring he means fibrosis – muscle tissue that has stretched and hardened until it no longer contracts. That means little in the quadriceps of a footballer. In a muscle such as the heart, however, scarring disrupts the electrical impulses that flow through the flesh, keeping that all-important beat steady. "From our evidence, about 12 per cent of elite athletes, particularly in their 30s and 40s, have these little patches of scar in their heart. A normal heart shouldn't have scar. But again, no one knows the significance of that."

Perhaps more confronting is what happens following long-term elite performance. The day Mercer died, a friend said he would be remembered as "the little bloke with the heart of Phar Lap", and the metaphor is not far off the truth.

The hearts of exceptional athletes are often massive: twice the size of a normal human heart. Sometimes, almost three times as large. But not by birth. The organ literally grows with training. Indeed, it would be impossible for a Tour de France cyclist to perform as they do without a big, bulging heart pumping away. Where a normal person has a 100-millilitre ventricle, says La Gerche, many endurance athletes have a 300-millilitre capacity. "The change in heart structure and function that occurs with exercise is profound. It's not subtle at all. In the chest of some of these guys, there's a fight going on for space."

The health implications of these big hearts, however, are unknown – hence a world-first study being conducted by La Gerche. He calls it the "Athletic Framingham" in a nod to a landmark longitudinal heart-disease study using people from the town of Framingham, Massachusetts. The new study – a collaboration between doctors in Australia and Belgium – began two years ago and is similarly longitudinal, but the subjects are selected for their exceptional athleticism.

La Gerche takes hundreds of high-level athletes – cyclists, triathletes, cross-country skiers, rowers and runners – and examines their heart function, then does so again after two years, five years, 10 years and 25 years. The regimen includes an ultrasound, VO2 Max testing, DEXA scanning (examining fat, muscle and bone strength), heart-rhythm monitoring, and even an "exercise MRI" in which the subject is strapped to a horizontal ergometer (a recumbent cycle), then pedals on their back while sliding into an MRI scanning tube.

La Gerche obviously resents alarmists peddling "myths" in his field, but he isn't ignoring legitimate concerns. Endurance athletes, he says, are somewhere between 2 per cent and 5 per cent more likely than the general population to develop heart problems. Yet there is no evidence that years of endurance exercise will shorten your life. He wants to reconcile such findings. "The research is a scratch and sniff thing," he says. "It's not like I can solve this issue by doing more reading. No one knows the answer."

Champion triathlete Emma Carney competing in 1998, before heart trouble brought her career to a premature end.

Champion triathlete Emma Carney competing in 1998, before heart trouble brought her career to a premature end.Credit: Getty Images

Yet the question has been raised, even by people La Gerche has consulted. People like 46-year-old Emma Carney, the former champion Australian triathlete. Two decades ago, Carney was the dominant force in the most gruelling event on the planet, until she developed a heart condition that threatened her life, and forced her to abandon a glittering career. La Gerche has seen her training diaries. He breaks his words apart when describing what she could do.

"Un. Believable," he says. "Out. Rageous." He has never met an athlete – male or female, at any level – who could punish the human body as Carney did. "If it is possible to overtrain your heart," he says, "Emma is example one, two, three and four."

I meet Emma Carney at Melbourne Girls Grammar school in South Yarra, where the two-time World Triathlon Champion is now a running coach. She is still slender, and muscular, and seems to enjoy reliving her glory days. We sit on a balcony outside the gym, and the sky is clear, so the view stretches to the Dandenong Ranges and Eltham, where she grew up, and where, she tells me, in a single week she used to swim 35 kilometres, cycle 400 kilometres and run 100 kilometres.

"I just thought that's what you did as an athlete – you train as hard as you can so the race is a picnic. And most of the time, it was," she says, clearly retaining her competitive confidence. "I had a good, low, resting heart rate. Good lactic tolerance, too. It allowed me to stay at that pain threshold, but it also probably caused damage to my heart."

It was 1998 when problems arose. She was 26, and coming off a year in which she had won almost every major triathlon in the world, but she didn't feel great. She felt dizzy and fatigued – suddenly unable to bury her opponents. Things got serious in 2004, while on a national team training camp in Edmonton, Canada. A wave of weakness washed over her during a regulation swim and, after six years fighting against a phantom lethargy, Carney was exasperated.

"My heart was racing in my chest, and I actually thought it was a panic attack. I thought I had gotten that pathetic that I was having anxiety over training!" Soon she was in an ambulance. She told the paramedics not to worry if her enviably low heart rate looked a little odd. "And they went, 'Um, no, your heart rate is 248. You're in cardiac arrest.' "

In hospital, her hands and feet went numb. The doctors stood back, and she wondered why, until she felt the jolt of a defibrillator. "It was like being hit by a truck, but with no splatter. You come up off the bed as your muscles tense. But there was immediate relief … as soon as I stopped swearing!"

Much later, others examined her electrophysiology. She was diagnosed with an arrhythmia known as ventricular tachycardia, or VT – the same condition that forced Australian triathlete Greg Welch to abandon the sport. "The electrical signals basically aren't being received as they should, and so the heart twitches instead of beating normally, and if it twitches for long enough, it fatigues and gives up, and goes into ventricular tachycardia," Carney explains. "Usually your heart can only sustain VT for 10 minutes, but my heart is extraordinarily big and strong and can bang away in an arrhythmia longer than it should be able to. It's like the rest of my body – it can overdeliver on pain."

Emma Carney, now 46, is restricted to light exercise these days.

Emma Carney, now 46, is restricted to light exercise these days.Credit: Damien Pleming

Carney had a defibrillator installed beneath her left breast. She has a new one now, and hands me the old. She expected something as tiny as a sim card, but the Epic Plus VR is about the size of a thin yo-yo. She points to the holes where the wires go. "Apparently, if you get a paperclip and shove it down there, you could give yourself a defib," she grins. "I wouldn't though."

Hers has gone off half a dozen times, always when she pushes herself too hard. She can jog lightly for hours, but if she attempts a beep test, she'll fall into immediate distress. She set it off 18 months ago, doing one-kilometre sprints. Too many, too quickly, with too little recovery time. "My doctor – 'the prof' – he never laughs," she says, smiling. "He just looks at me like, 'We're not getting the message are we, Emma?'"

Professor Richard Harper is one of the most respected cardiologists in Australia. He began seeing Carney in 2004 at his consulting suite at Monash Medical Centre in Clayton, south-east of Melbourne.

He found scar tissue and an enlarged right ventricle. He believes these problems would not have developed without the extreme effort Carney put into her training – but he also notes that others could do similar training and never develop her issues. "I suspect she may have had a genetic predisposition," Harper says. "Certainly her younger sister is one factor that would be evidence in favour of that proposition."

He is referring to Clare Carney, a former junior world champion triathlete who was plucked, floating face down, from her swimming lane at the Melbourne Sports and Aquatic Centre in 2012. Clare had suffered a cardiac arrest during a lap turn and was clinically dead for 40 minutes before being resuscitated.

Both sisters having heart conditions does suggest a potential genetic risk factor, he says, but no one can be certain. It is an incredibly complicated area of medicine. Here Harper chooses his words carefully. "It is true that extreme exercise over a long period of time in a small percentage of patients can entail some risk," he says. "But anything that discourages people from exercise or gives them an excuse not to is detrimental."

He understands the interest. When a superb athlete dies, people blame the sport, but such victims are statistical outliers. Research suggests, for instance, that about one in 100,000 people die of heart attacks during marathons. "These events are pretty rare, and to draw general conclusions from them is very, very dubious," says Harper. "But it makes a great story."

The most popular version of that story begins in Missouri, with Dr James O'Keefe, a cardiologist who authored a paper titled Potential Adverse Cardiovascular Events from Excessive Exercise, then turned it into a 2012 TED Talk, viewed more than 650,000 times.

O'Keefe, 61, speaks smoothly in his 18-minute presentation, combining catchy one-liners – "It's not survival of the fittest, but survival of the moderately fit" – with common sense. He says, for instance, that moderate daily exercise – even a brisk walk for 30 minutes – is more than enough activity to promote longevity, and also that serious running, swimming and cycling have diminishing returns. Experts on both sides of the debate acknowledge the same truths.

He also comes from an athletic background, having won several triathlons in Kansas City, so he has street cred when talking about his fear he may have run too hard and too fast "towards the finish line of life". He has charisma, and so his views were circulated immediately, given a boost by an article in The Wall Street Journal headlined: "One running shoe in the grave."

He tells Good Weekend that his epiphany came when his own heart became irritable. "It just dawned on me that it's kind of an unproven assumption that 'more is better' when it comes to exercise," he says by phone. "It's not a particularly radical concept that overdoing it is not good for you." And so he still jogs, but sometimes walks, and other times does yoga. He says he is "training to see more sunsets".

His opponents argue, however, that athletes see more sunsets than most. High-level endurance athletes, in particular, see far more sunsets. O'Keefe doesn't want to spend time arguing over his thesis, but he acknowledges that it is controversial. "In other ways, it's not. If you want to do a marathon or climb Mount Everest, do it once, feel good about it, brag about it, whatever, but then settle into a moderate routine. I've been accused of making up data, or interpreting with bias. But I only have one agenda, the health and wellbeing of people. Some people want to kill the messenger."

Pointedly, his TED Talk begins with the story of a messenger – that of Pheidippides, who famously ran 42 kilometres from Marathon to Athens. He delivered news of victory in battle, then dropped dead. What most of us don't know, says O'Keefe, is that Pheidippides was an accomplished runner – a Greek herald messenger his entire life. "I'll bet he was the fittest guy in Athens the day he died," he says. "Strange."

The debate on the effect of exercise on the body – or more specifically the heart – has been going on for decades. In the 1970s, for instance, a US pathologist named Dr Thomas Bassler gained a degree of notoriety for what is known as the "Bassler Hypothesis". He believed that anyone who trained until they were capable of running a marathon would have 100 per cent immunity from coronary heart disease. The idea was quickly disparaged, but it also endured.

Dr Ross Walker, the Sydney preventative cardiologist, notes another famous name: Jim Fixx. The author of a 1977 best seller, The Complete Book of Running, Fixx suffered a heart attack at 32, then famously spurned a life of cigarettes and fatty food and latched on to running. His story ended in 1984, at the age of 52, when his heart gave out on a training run in Vermont.

Jim Fixx, photographed seven years before his death of an apparent heart attack in 1984.

Jim Fixx, photographed seven years before his death of an apparent heart attack in 1984.Credit: AP Laserphoto

"He thought running would be his saviour, and of course it wasn't," says Walker. One other thing? Six weeks before Fixx died, he had chest pains – but people told him he was too fit to worry. "That's how ingrained this idea was, that running a marathon could make you immune to a heart attack."

Such dreams of athletic invincibility came of age during the distance running boom, which most trace back to American runner Frank Shorter winning the 1972 Olympic marathon in Munich. Running was suddenly hip. US track stars like Steve Prefontaine were household names, gracing the cover of Sports Illustrated. Locally, and later, Robert de Castella set a 1981 world record for an out-and-back marathon in Japan and in 1982 won Commonwealth Games gold.

These feats brought long distance running into the minds of mortals. The Canberra Marathon was the first capital city "community marathon" in Australia when it began in 1976. Prior to that, officials were worried that the distance was too far for most people to endure. The marathon was one of the first Olympic events, but for the average person, completing one is a relatively recent aspiration.

South Australian marathon runner and former Bureau of Statistics worker Ian Hill compiled a statistical analysis of the Adelaide Marathon, which launched in 1979. The average runner there now is around 43, but back then it was 33. They were Baby Boomers, and Hill says a common axiom circulated among them: if you completed a marathon, you would be immune from heart attack for seven years.

Like most, Hill remembers the celebrated Fixx. He offers an alternate reading of his death. "Some people think running killed Jim Fixx, but who knows? Who's to say? It might have actually given him an extra five years of longevity."

Unfortunately longevity doesn't stand out in the same way that death does. Running the New York City Marathon more than a decade ago, I saw a man stumble in the early stages. He cracked his head in front of me, falling on the Verrazano-Narrows Bridge. He was helped immediately by officials, and I kept running. Later, after two of my toenails fell off at the finish in Central Park, I learnt that he had died of heart failure. Whenever this happens, such people become news items that pings around the internet, often with the same conflicting commentary.

But conflating the death of average runners with the arrhythmias of world champions can be problematic. "A regular marathon can confuse the entire question," says La Gerche, "because you're basically condensing a whole lot of old people into one very big stress test."

Confirmation bias begins to emerge, whereby any death offers "evidence" of a lurking suspicion. There's also "the exercise paradox" which states that if you're destined to have a heart attack, it is far more likely to happen when you are exercising. La Gerche says that during exercise, when you're fit, the risk of having a heart attack goes up about seven-fold. If you're unfit, it goes up 700-fold.

Such statistics would comfort Matt Ross. As the 22-year-old Melbourne cyclist enters La Gerche's laboratory for a V02 Max test, he pushes a finely tuned $6000 bike by his side. Soon he's wearing sensors and an oxygen mask. On a stationary bike he pedals against increasing resistance while machines measure how furiously his heart is pumping blood. The heart of a typical person, while sitting on the couch, pumps around five litres of blood per minute. During exercise, maybe 15 litres per minute. "Matt will get up to 30 or 40 litres per minute," says La Gerche. "Oxygen is just flying out to his muscles."

Ross flies to Paris tonight, and in two days' time will be pedalling the "Signal de Bisanne" route through the French Alps near the Swiss border. But in three years, no matter where his career goes, Ross will be back here. He joined the study because it will help future athletes, and help him to understand his body. "Even if there is a side effect to what we do – and I wouldn't be surprised if there was, given the stress we put on our bodies – it's fun," he says, shrugging. "Everything has its own risk factors and pleasures. I enjoy going for long rides, in challenging conditions, at high intensity."

La Gerche cannot wait decades for the Ross results to come in, so he has also devised a cross-sectional component of his larger study, examining older rowers (55 to 75) who once raced nationally. Compared with the average Australian, that cohort seem to be living longer, and living well, but are experiencing more heart-rhythm problems, specifically the disturbance known as atrial fibrillation.

"Most cases of atrial fibrillation fit into the nuisance category rather than the scary category," La Gerche says. "But it's there. We can't ignore that."

Jeff Watt, 73, is one such rower. We meet at a cafe near the boathouse where he coaches young rowers at St Kevin's College in Toorak. Watt was a national champion in coxless pairs, and once ran second at Henley Royal Regatta in the UK. He remembers training six days a week: rowing, circuit work, weights, but also running over sand dunes in bare feet, a regimen inspired by the old Stotan training philosophy of the legendary but eccentric Australian athletics coach, Percy Cerutty

"Everything was GO! GO! GO!" Watt says. "We'd do chin-ups the moment we came off the water, then chinups with a 25-pound weight around our waist. It was always hard. If you didn't do it, you were seen as soft." A retired secondary school vice-principal and surfer, Watt experienced his first taste of atrial fibrillation after a session in the waves at Torquay. The persistent flutter was worrying and now stops him from any intense physical activity. He can row only moderate warm-ups or his heart will thump in his chest.

He isn't ready to blame his former career. Had he not trained as he did, he wonders, would he have suffered even worse outcomes, even sooner? "It does make you think," he says. "I don't want to be a statistic."

The most robust fitness statistics, however, point in another direction: rising obesity throughout the developed world. Is this why we feel so compelled to finish a sprint triathlon, or Tough Mudder, or ocean swim? Economic imperatives and advertising are also driving us to push ourselves. Fitness culture was first commercialised in the 1980s, notes Dr Kim Toffoletti, an expert in sport and consumerism at Deakin University, but today it is utterly embedded.

The ubiquitous Fitbit might be the greatest culprit in our quest for efficient betterment, while a sportswear company such as 2XU is aligned with the Australian Institute of Sport. These companies are not just selling a piece of stretchy material to aid in recovery, says Toffoletti. They're selling a high-performance athletic identity.

"It's a profound shift from getting into your daggy trackie pants for a jog around the block," she says. "Does anyone even do that any more?"

Not right now they don't, at least not on the Tan Track, the beautiful 3.8-kilometre circuit around Melbourne's Royal Botanic Gardens. There are plenty of joggers out this sunny lunchtime, although at the peak of the Anderson Street hill most runners are now huffing walkers, albeit in Lululemon tights and Under Armour compression socks

The track sits just outside the school where Carney teaches, so she still runs or at least jogs lightly here often. When Carney surveys the view, she worries. She still wonders if her own professional workload was too much for the heart to bear. Anything in excess, she suspects, is dangerous. "And elite athletes really don't understand balance," she says. "You can never settle – you're always pushing boundaries."

She is perhaps more concerned, though, for the groups of guys she sees here in their 40s. They get out of their flash cars, then thrash out a violent lap or two. Why not warm up a little? Or run-walk a bit?

Carney stares down the hill at one such guy, lumbering towards her at speed. He probably played footy in his youth, she says, because he has that residual muscle definition.

"He's obviously put on a bit of weight. Now he wants to take it off, and he's trying to rip up this hill," she says, sighing. "We all know you can pull a hammy. But maybe you can pull a heart, too."

To read more from Good Weekend magazine, visit our page at The Sydney Morning Herald or The Age.

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