David, Thanks for the link. I would tend to agree that the data about scar formation is concerning. I am not sure what can made of reversible RV dysfunction. Perhaps the perfect storm is one of a veteran athlete who has previously developed some scar, has a good sense of how hard to push during an event and then the "event related" RV dysfunction becomes arrhythmogenic in the susceptible (i.e. scarred) heart.
I'd be overweight and hypertensive if I didn't exercise and the only way I've ever been able to stick with it is to race and I really like to race long course tri's therefore I'm better off than a sedentary, overweight slob w/ a poor lipid profile! Not to mention depressed and miserable.
x2 on what Jeff said. 3 yr's ago I was 230lbs, my cholesterol was through the roof, and I was largely sedentary. Now I'm in great shape and all of my numbers are better. Would several LSD runs be moderately better for my heart? Maybe. But even if that were actually proven to be true (which it hasn't been), I'd rather die crushing myself to achieve something I feel is meaningful in my life.
@John Good for you. That's awesome. My personal back story is I was 35 lbs heavier 12 years ago, developing high blood pressure, tension headaches, had high triglycerides, low HDL, was not really enjoying my life and family history of diabetes, etc. 12 years later I'm keeping the weight off, BP and lipids are AWESOME and I LOVE my life.
Triathlon is LIVING and we all have a limited time on the planet. ENjoy your time as it is too short and we never know when our time is up. I'm not endorsing going out and purposely killing yourself doing something totally insane but you gotta live.
As someone who suffers from cardiac scarring, this issue is no joke. I'm having to reevaluate the priorities in my life, looking further down the road than the next PR. Damned sobering.
@Bill Hate to hear this. How was scarring determined? My overly cautious internist ordered an echo for me last Christmas and all was normal. He was worried about my athlete's heart and didn't have enough experience with it and he is pretty conservative.
@David, I believe the study focused more on long events between 3 and 11 hours, not short, frequent, intense exercise. So I would say that it makes me wonder about repeatedly competing in 3+ hour high intensity events.
[Disclosure: I am not a cardiologist, and while I may *sound* intelligent, everything I say could be purely random speculation based on poorly remembered 40 year old infoormation from medical school.]
I read the full article (not in print yet, had to get it through my medical library's online access code) and have a few thoughts.
• Interesting tidbit: the study, from Australia, looked 3 hour marathoners, 5.5 hour HIMers, 8 hours/200 km cyclists, and 10.5 hour IMers, about ten each. The heart size of the IMers and the marathoners were the same, and larger than the other groups.
What they basically found was evidence of heart muscle damage, reduced heart function (right side only), and, in *five* of the 40 athletes studied, fibrosis of the heart muscle between the two ventricles. Importantly, they studied the heart function 2-3 weeks before, immediately after, and 6-11 days after the race; the test for muscle damage were done before and immediately after, and the test for scarring was only done 2-3 weeks *before* the races.
Describing muscle damage post race is simply stating the obvious. For those who have ever done one of these races, remember how your thighs felt for a few days to a week afterwards - they hurt, and your legs couldn't move as well. That's cause you've got *muscle damage* in your quads. Your body knows how to repair that, and it does. A few weeks later, you can start runing again, and your legs eventually will work all right. Same concept with the heart, it seems to me. The heart muscle is very good at repairing the minor damage which occurs during these races. It is *not* the same as the damage which occurs during a heart attack. Then, the blood flow is disrupted, and the muscle dies. In our case, the blood flow is just fine, which is why repair can occur. The study also demonstrates the obvious, that the damge is greatrer and the repair takes longer, the longer the race. Age, weekly training volume, or years of endurance sport competition did *not* seem to affect the repair process.
But apparently, over time, there is a risk of that repair leading to fibrosis, or scarring, which has the potential to lead to dealy arrhythmias
Why is scarring scary? The heart is a muscle with a intrinsic electrical system which causes a coordinated contraction about once a second. The electrical system can be interrupted if there is scarring, and thus rhythm disruption can occur. Cardiologists know about this mostly from people who have heart attacks which damage the muscle, and then a rhythm disturbance can occur. Depending on the specific timing of the disruption, this can be an annoyance or deadly. So these guys found scarring in 20% of the athletes. It was more liklley to be found in those who were longer term athletes (20 vs 8 yrs), with a greater predicted VO2 max. They also had larger hearts, but that goes along the the greater VO2 max. So, knowing what they do about post MI patients, they speculate that these guys might be at greater risk for a deadly arrhythmia.
Remember, all of the scarring was found *before* the race, via a cardiac MI gadolinium injection (I have no idea what that is). So, theoretically, one could be screened for this, and then evaluated further by a cardiologist if scarring were found.
My takeaway? Rethink the timing of races within 3-4 weeks of each other (maybe including the final race rehearsal before an Ironman?) IM: no closer than 4 weeks; race rehearsal: 3 weeks seems to be cutting it close; marathon and HIM: 2 weeks spearation. Also, next year, after this article has come out in print, I'll get a referral to a cardiologist and see if I can finagle a cardiac MI.
Still and all, I'm much more worried about prostate cancer and freeway crashes than I am about a deadly arrhythmia from too much exercise and racing. In the past 10-15 years, there have been 1000's of elite IM athletes training and racing. If this were a significant issue, we should have started hearing about it from doctors in Colorado, California, etc. Or, maybe this is the canary in the coal mine.
Al that is a nice review and explanation. I also agree that there are other issues that can lead to my death associated with training and racing that I am more worried about a than developing a fatal arrhythmia due to exercise induced right ventricular cardiomyopathy. However, if I had scarring present and/or an arrhythmia that originated in the right ventricle I would be a lot more concerned. I would also agree that the damage to the heart is repairable just like to the thigh muscles, however that healing will take longer and studies have indicated that the dysfunction of the right ventricle is still present for up to 4 weeks following the event. I also do not know what the training plans of those involved in the studies were but there is likely a lot of volume and training time in the weeks prior so not sure it changing the timing of the RR is indicated for me personally.
I do think and will say again that I believe that we need to take more time off after an endurance event not just space out the event but take time off from racing and training to allow our hearts to heal. For me currently that will be 2-3 weeks with no training only stretching following an endurance event and and no restarting of serious training for 4-6 weeks.
Bill sorry to hear of your issues. I hope all works out well for you.
This study of 40 endurance athletes found evidence of right ventricular effects after an endurance event that largely resolved by six to 11 days later.
Also, no concomitant left ventricular effects were observed.
Review
Intense endurance exercise -- such as running a marathon -- may induce cardiac damage confined to the right ventricle, a small study showed.
Highly trained endurance athletes had reductions in right ventricular function immediately after a race, although it mostly returned to normal about a week later, according to André La Gerche, MBBS, PhD, of the University of Melbourne in Australia, and colleagues.
However, a handful of the athletes had signs of subclinical myocardial scarring on cardiac MRI, "suggesting that repetitive ultra-endurance exercise may lead to more extensive right ventricular change and possible myocardial fibrosis," the researchers reported online in the European Heart Journal.
There were no changes in left ventricular function, which "provides further circumstantial evidence for the emerging concept that the right ventricle may be more susceptible to exercise-induced injury [than the left]," they wrote.
The study included 40 athletes (mean age 37) who were participating in a marathon, an endurance triathlon, an alpine cycling race, or an ultra triathlon. All trained for more than 10 hours a week and had finished in the top quarter of a recent endurance race. None had cardiac symptoms or risk factors.
The researchers evaluated the athletes two to three weeks before the race, immediately after the race, and six to 11 days after the race.
Compared with baseline, right ventricular volumes increased, and all measures of right ventricular function worsened immediately post race. Left ventricular function was unaffected.
Levels of two biomarkers of myocardial injury -- cardiac troponin I and B-type natriuretic peptide -- significantly increased following the race (P=0.003 for both). The changes were associated with reductions in right ventricular ejection fraction (P=0.002 for both), but were unrelated to left ventricular ejection fraction.
Lower right ventricular ejection fraction was significantly associated with longer race duration and increasing peak oxygen uptake (P=0.011 for both).
By six to 11 days after the race, most measures of right ventricular function had returned to normal, with the exception of right ventricular strain rates, which remained lower.
In the 39 athletes who underwent cardiac MRI, five had delayed gadolinium enhancement confined to the interventricular septum, indicative of subclinical myocardial fibrosis. These athletes had been competing in endurance sports longer and had lower right ventricular ejection fractions compared with those with normal MRI findings.
Because the study was not powered to assess clinical outcomes, the significance of the MRI findings requires further study, according to the authors.
The study "begs the hypothetical question whether repetitive longstanding bouts of arduous exercise result in the development of an acquired form of arrhythmogenic right ventricular cardiomyopathy," Sanjay Sharma, MD, and Abbas Zaidi, MBBS, of St. George's University of London, wrote in an accompanying editorial.
"The results provide food for thought and the data should be embraced to galvanize more detailed and longitudinal assessment of large groups of endurance athletes," they wrote. "The potential for such projects is enormous considering the colossal increase in participation rates in endurance events such as the marathon."
La Gerche is supported by a postgraduate scholarship from the National Health and Medical Research Council in Australia. The project was financed, in part, by a Cardiovascular Lipid Grant from Pfizer Australia.
The authors reported that they had no conflicts of interest.
The editorialists reported that they had no conflicts of interest.
Primary source: European Heart Journal
Source reference:
La Gerche A, et al "Exercise-induced right ventricular dysfunction and structural remodelling in endurance athletes" Eur Heart J 2011; DOI: 10.1093/eurheartj/ehr397.
Additional source: European Heart Journal
Source reference:
Sharma S, Zaidi A "Exercise-induced arrhythmogenic right ventricular cardiomyopathy: fact or fallacy?" Eur Heart J 2011; DOI: 10.1093/eurheartj/ehr436.
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New research links endurance exercise to damage in the right ventricle of the heart
Date: 07 Dec 2011 Embargoed: 00.05 hrs (GMT) Wednesday 7 December 2011
Researchers have found the first evidence that some athletes who take part in extreme endurance exercise such as marathons, endurance triathlons, alpine cycling or ultra triathlons may incur damage to the right ventricles of their hearts – one of the four chambers in the heart involved in pumping blood around the body.
The research, published online today in the European Heart Journal [1], found that although the damage was reversed within a week of a competitive event in most of the 40 athletes studied, five of them (13%) showed evidence of more permanent damage, with magnetic resonance imaging (MRI) showing scarring of the heart muscle (known as fibrosis). These five had been competing in endurance sports for longer than those who did not show the same damage.
Dr André La Gerche (MD, PhD), a postdoctoral research fellow at St Vincent’s Hospital, University of Melbourne, Australia, but who is currently based at the University Hospitals Leuven, Belgium, said: “It is most important that our findings are not over-extrapolated to infer that endurance exercise is unhealthy. Our data do not support this premise.”
However, he said that the findings did suggest that there might be some athletes who might have been born with a susceptibility to develop damage as a result of long-term endurance exercise.
“Virtually all of the changes in the athletes’ hearts had resolved one week after having taken part in a competitive event. In most athletes, a combination of sensible training and adequate recovery should cause an improvement in heart muscle function; that is, the heart rebuilds in a manner such that it is more capable of sustaining a similar exercise stimulus in the future. This positive training response can be over months rather than weeks,” he explained. “The question from our research is whether there are some athletes in whom extreme exercise may cause injury from which the heart does not recover completely. If this occurs, affected athletes may be at risk of reduced performance – a cardiac ‘over-training’ syndrome – or it may cause arrhythmias. If this occurs, it is likely to affect only a minority of athletes, particularly those in whom more intense training fails to result in further improvements in their performance.”
Dr La Gerche and his colleagues in Australia and Belgium recruited 40 elite athletes in Australia who were planning to compete in one of the four endurance events [2]. The athletes were already well trained (training intensely for more than 10 hours a week), performing well (having finished within the first 25% of the field in a recent event), and had no known heart problems.
The researchers studied the athletes, using echocardiography, MRI, and blood tests, at three time points: two to three weeks prior to the race, immediately after the race (within one hour), and 6-11 days after the race.
Results showed that immediately after the race the athletes’ hearts had changed shape, with the volume increasing, while the function of the ventricle decreased. Levels of a chemical called B-type natriuretic peptide (BNP), which is secreted by the ventricles in response to excessive stretching of heart muscle cells, increased. Right ventricle function recovered in most athletes after one week, but in the five who had been training and competing for longer than the others, MRI detected signs of scarring (fibrosis). The researchers also found that the post-race changes to the function of the right ventricle increased with the duration of the race.
In contrast, the left ventricle, which, up to now has been the most studied in athletes, showed no changes.
Dr La Gerche said: “Our study identifies the right ventricle as being most susceptible to exercise-induced injury and suggest that the right ventricle should be a focus of attention as we try to determine the clinical significance of these results. Large, prospective, multi-centre trials are required to elucidate whether extreme exercise may promote arrhythmias in some athletes. To draw an analogy, some tennis players develop tennis elbow. This does not mean that tennis is bad for you; rather it identifies an area of susceptibility on which to focus treatment and preventative measures.”
He concluded: “It is important to note that this is one component of an evolving understanding of how the right ventricle is the ‘Achilles heel’ of heart function during exercise. We previously studied heart function during intense exercise and demonstrated that the load on the right ventricle (stress, work and oxygen demand) increases to a greater extent than in any of the other heart chambers. Professor Hein Heidbuchel, who I work with, has shown that the source of ventricular arrhythmias in affected athletes is almost always the right ventricle. Finally, it has been shown that intense exercise in rats causes inflammation, fibrosis and arrhythmias in the right but not the left ventricle. Hence, there are consistent messages, all implicating the right ventricle and yet it has been neglected in the vast majority of studies regarding cardiac changes in athletes. Now there is sufficient evidence to invest in the long-term prospective studies that are required.”
In an accompanying editorial [3], Professor Sanjay Sharma, of St George’s University London (UK), who is medical director of the London Marathon, writes that although the study is small, “the results provide food for thought and the data should be embraced to galvanise more detailed and longitudinal assessment of large groups of endurance athletes. The potential for such projects is enormous considering the colossal increase in participation rates in endurance events such as the marathon. The long-term conclusions of the authors may appear preposterous to some, but could prove to be the retrospective ‘elephant in the room’.”
In a statement for this press release, Prof Sharma said: “My personal feeling is that extreme endurance exercise probably does cause damage to the heart in some athletes. I don’t believe that the human body is designed to exercise at full stretch for as long as 11 hours a day, so damage to the heart is not implausible. It is too early to say that taking part in endurance sports causes long-term damage to the right ventricle, but this study is an indication that it might cause a problem in some endurance athletes with a predisposition and, therefore, it should be studied further.”
(ends)
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Emma Mason
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Email: wordmason@mac.com
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Notes to editor
The European Heart Journal is the flagship journal of the European Society of Cardiology. It is published on behalf of the ESC by Oxford Journals, a division of Oxford University Press. Please acknowledge the journal as a source in any articles.
[1] “Exercise induced right ventricular dysfunction and structural remodelling in endurance athletes”. European Heart Journal. doi:10.1093/eurheartj/ehr397
[2] The distances for each event are as follows: marathon = 42.2 kms; endurance triathlon = 1.9km swim, 90 kms cycle, 21.1 kms run; alpine cycling = 207 kms; ultra triathlon = 3.8 kms swim, 180 kms cycle, 42.2 kms run.
[3] “Exercise-induced arrhythmogenic right ventricular cardiomyopathy: fact or fallacy?”. European Heart Journal. doi:10.1093/eurheartj/ehr436
I do not wish in any way to minimize the seriousness of the issue under study, but it never ceases to amaze me how medical researchers (or bloggers like Dr. John) constantly violate some of the basic premises of scientific study...and especially about not extrapolating beyond the bounds of your data. I've always felt that the medical field was especially prone to shoddy research or at least spectacularly unsupported conclusions. We are told that the individuals were elite but we are not given their times or places against their field. We are not told their athletic history (was damage greater in those who approached these events with more or less experience?) We are not given any measure of anaerobic intensity. We do not know if the damage was lasting (the latest measures were 11 days post race). We are unable to determine from the published results whether the deleterious effects are worse in much shorter, but vastly more intense anaerobic workload (e.g., a 5K in sub 13 mins by a world class runner) as opposed to an ironman by an age grouper at an entirely aerobic pace. We are not given the variance in measured scarring between marathons and triathlons, and whether the difference is statistically significant. The results are not paired against the performance level in an age-graded manner or some other method of normalizing to determine if scarring is indeed correlated with intensity. And yet, despite the tremendous methodological shortcomings, heroic conclusions are drawn (at least by Dr John) without any balance or mention of countless longitudinal studies that have documented the tremendous benefits of exercise amongst athletes who have been at it for decades...the same types of people who are most likely to engage in longest endurance events.
There have always been studies that people could point to if they want to avoid exercise...just add this one to the list. Need I mention that medical science as recent as the 1970's was justification for keeping women's olympic events to 3000m and less? And while the implications of this current research are extraordinarily serious, I don't believe the authors or the rest of medical science have a full understanding of the lasting impacts of intense or extended exercise (they differ). I can only agree with them that further longitudinal research is necessary. Meanwhile, having been a long distance runner for over 4 decades, I will lose no sleep over this. In fact, it's time for me to head out the door and run.
If I didn't have my endurance exercise and training, I would probably still weigh 350 lbs and be waisting my life away on the couch, or in front of a computer. I would rather my number be up when I'm doing something I love like running or cycling that to have it come up in front of the computer, or driving somewhere in a car.
One thought on this: it might make sense for endurance athletes to take a "breather year" once in awhile, just like we take rest days in our training weeks, and light weeks in our training cycle for the year.
I tend to cycle through years where I do long distance HIM, marathon, or IM races, years where I do shorter distances like Oly's, sprints, and shorter running or cycling events, and the occasional year where I don't do any competing or just do a couple of small fun races. This last summer was planned as a no race year. I did some fun events (a 6.4 mile swim across Crater Lake with some friends, a 24 mile trail run with my hubby and BIL supporting me on mountain bikes) but neither of those was at anything approaching a race intensity. They were experiences, not races. Other experiences have included learning martial arts, being on a skydiving team, riding the Seattle To Portland, climbing Mt. Kilimanjaro. I know that in those kind of conditions, I don't push myself the way I do when I'm five miles from a finish line in a race situation.
I guess I'm saying that it doesn't have to be either/or - either I'm a couch potato or I do Ironmans every year. There are so many different things out there to experience and enjoy. Rotating through competitive times and less competitive times may indeed be better for our health (and heart) than pushing it to the limit year in and year out. This is just my n=1 with 25 years in the sport, still being competitive and still loving it.
All I know is I am one of those endurance athletes who developed Afib. To me, it was out of NOWHERE. I have ZERO other risk factors--no family history, no HBP, no diabetes, no ischemic heart disease, no structural deformity of the heart. It started when I was training for IMWI, coupled with a life-threatening cycling accident suffered by my husband. The docs feel the stress of BOTH was likely contributory.
I had parosysmal (lone) Afib, and had an ablation on 9/15. I have not had an episode since the ablation, but that doesn't mean it will never return. I may or may not be cured for good. Although every passing month the outlook gets better, although it can come back even years form now.
Trust me when I tell you, if you develop an arrythmia--and there is NO DOUBT that it is more prevelant in endurance athletes--it will change your life. And not for the better. I, literally, have scars on my heart from the procedure. I wish that on no one. I am getting back to training strong, but it is an uphill climb.
I signed up for IMFL, but am thinking long and hard about that. The docs are ambivalent. They really WANT me to exercise, and love the idea of running 5-6 miles and cycling a couple of hours. The rest? Well, they just don't have enough evidence yet, although a lot is pointing to the negative. They think these studies are, indeed, "the canary in the coal mine," but as we all know, it's complicated with much variabilit per the individual.
It's extremely difficult to turn away from the endurance triathlon, that much I know too.
@ Linda - You are an amazing athlete; and I sure hope you are permanently cured. Maybe I've been lucky and I'm at risk of developing an arrythmia in the near future, but until the science is vastly more predictive I have no intention of changing my habits. I believe that some people for unknown reasons may be more susceptible to these kinds of problems. Otherwise, Hillary Biscay would long be dead. Or what about Stephan Engels of Belgium who recently ran 365 consecutive marathons...in one year's time? I've long felt that if I were able to hurt my heart it would have happened between ages 26-31 when I had the ability to push myself as a runner to the edge and beyond. Now that I'm a triathlete (and much older), I train longer, but there is nothing I do that I would remotely consider as intense as the running I did back in those years. My resting pulse is typically around 46-50, and Z4 work on the bike doesn't get me much over 140 bpm. That's another area the study above failed to look at (or at least report on)...e.g., is their any correlation between heart damage and the individuals resting pulse? Again, maybe I've just been lucky, or maybe it's not luck at all and I have some genetic trait that makes me less susceptible to this...don't know. But the older I get, the less I worry about this kind of research.
I'm one of those that is always shifting focus from year to year. Some years iron long, some years oly's, some years ultra long, some years half's. I do it so that I don't get stuck in a rut. I do it because I can't afford ($) to go long every year. But, I do believe that there is some physiological benefit to mixing it up. It's not like I'm a pro that has to performs 'X' distance 'y' amount of time with 'z' results to get paid.
I'm healthier for doing multisport stuff, bottom line. If my heart fibrillates or flutters, or I have that 'can't catch my breath' sensation (the one that's different than after the hard intervals), I back off. Otherwise, the way I see it, I only have so many grains of sand in the hourglass. And I have no idea as to how many there are or when they'll run out. So, I gotta go play, c ya!
Folks, this is an important discussion, and I respect viewpoints on both sides. I still haven't made up my own mind about what I think about it all.
I too am someone who had become sedentary before discovering a love for running and then tri. And yes, I find that working out and competing do make me feel alive.
However, out of respect for the Gleason family, can we please agree to discontinue use of the phrase "I'd rather die than...". Let's not forget Chris' constant admonition: this is all recreational athletics, it's just a game. Let's not take it too seriously.
However, out of respect for the Gleason family, can we please agree to discontinue use of the phrase "I'd rather die than...". Let's not forget Chris' constant admonition: this is all recreational athletics, it's just a game. Let's not take it too seriously.
Thanks for saying that Mike. I cringe whenever someone says something like "I'd rather die running, racing,whatever than infirmed in a bed or as a couch potato, blah, blah, blah." As if those are the only choices available. Life doesn't have to be extreme.
No offense to anyone who stated that in this thread (as I haven't read through it) but it's just a f**king stupid thing to say. Nobody would choose dying young in the pursuit of a hobby. EVER. It's ridiculous. There's isn't one damn person that says something like that and actually means it. Get some perspective, folks.
@Mike Excellent point and I hope no one is saying that. I've taken care only to be positive and make the statement that one has to enjoy their one and only life to the fullest. Triathlon is a major part of my enjoyment and I hope it continues to be.
I think if anyone did make a statement to that effect, it is likely something they said off the cuff and mostly b/c it is such an uncomfortable subject particularly with Chris' demise. I think there is an aura of invincibilty associated with high levels of fitness and it is hard for most of us to accept our mortality, kind of like when you were in your teens or 20's. Never thought about dying or death too much back then. In your 40's, 50's, etc....more in your mind. Not to mention dying slowly from a progessive, chronic ailment. That's unpleasant to think about and why many people say things like "I hope I have a heart attack in my sleep" or the like.
If anyone has made a statement to the effect of "I'd rather die racing..." I'm willing to avoid judging them b/c I feel they may be dealing w/ Chris' loss and perhaps their own issues in their own way but I also hope there are NO more posts to that effect.
Comments
I'd be overweight and hypertensive if I didn't exercise and the only way I've ever been able to stick with it is to race and I really like to race long course tri's therefore I'm better off than a sedentary, overweight slob w/ a poor lipid profile! Not to mention depressed and miserable.
How's that for rationalization???
but how do I feed my endorphin addiction if I stop
@John Good for you. That's awesome. My personal back story is I was 35 lbs heavier 12 years ago, developing high blood pressure, tension headaches, had high triglycerides, low HDL, was not really enjoying my life and family history of diabetes, etc. 12 years later I'm keeping the weight off, BP and lipids are AWESOME and I LOVE my life.
Triathlon is LIVING and we all have a limited time on the planet. ENjoy your time as it is too short and we never know when our time is up. I'm not endorsing going out and purposely killing yourself doing something totally insane but you gotta live.
As someone who suffers from cardiac scarring, this issue is no joke. I'm having to reevaluate the priorities in my life, looking further down the road than the next PR. Damned sobering.
@Bill Hate to hear this. How was scarring determined? My overly cautious internist ordered an echo for me last Christmas and all was normal. He was worried about my athlete's heart and didn't have enough experience with it and he is pretty conservative.
[Disclosure: I am not a cardiologist, and while I may *sound* intelligent, everything I say could be purely random speculation based on poorly remembered 40 year old infoormation from medical school.]
I read the full article (not in print yet, had to get it through my medical library's online access code) and have a few thoughts.
• Interesting tidbit: the study, from Australia, looked 3 hour marathoners, 5.5 hour HIMers, 8 hours/200 km cyclists, and 10.5 hour IMers, about ten each. The heart size of the IMers and the marathoners were the same, and larger than the other groups.
What they basically found was evidence of heart muscle damage, reduced heart function (right side only), and, in *five* of the 40 athletes studied, fibrosis of the heart muscle between the two ventricles. Importantly, they studied the heart function 2-3 weeks before, immediately after, and 6-11 days after the race; the test for muscle damage were done before and immediately after, and the test for scarring was only done 2-3 weeks *before* the races.
Describing muscle damage post race is simply stating the obvious. For those who have ever done one of these races, remember how your thighs felt for a few days to a week afterwards - they hurt, and your legs couldn't move as well. That's cause you've got *muscle damage* in your quads. Your body knows how to repair that, and it does. A few weeks later, you can start runing again, and your legs eventually will work all right. Same concept with the heart, it seems to me. The heart muscle is very good at repairing the minor damage which occurs during these races. It is *not* the same as the damage which occurs during a heart attack. Then, the blood flow is disrupted, and the muscle dies. In our case, the blood flow is just fine, which is why repair can occur. The study also demonstrates the obvious, that the damge is greatrer and the repair takes longer, the longer the race. Age, weekly training volume, or years of endurance sport competition did *not* seem to affect the repair process.
But apparently, over time, there is a risk of that repair leading to fibrosis, or scarring, which has the potential to lead to dealy arrhythmias
Why is scarring scary? The heart is a muscle with a intrinsic electrical system which causes a coordinated contraction about once a second. The electrical system can be interrupted if there is scarring, and thus rhythm disruption can occur. Cardiologists know about this mostly from people who have heart attacks which damage the muscle, and then a rhythm disturbance can occur. Depending on the specific timing of the disruption, this can be an annoyance or deadly. So these guys found scarring in 20% of the athletes. It was more liklley to be found in those who were longer term athletes (20 vs 8 yrs), with a greater predicted VO2 max. They also had larger hearts, but that goes along the the greater VO2 max. So, knowing what they do about post MI patients, they speculate that these guys might be at greater risk for a deadly arrhythmia.
Remember, all of the scarring was found *before* the race, via a cardiac MI gadolinium injection (I have no idea what that is). So, theoretically, one could be screened for this, and then evaluated further by a cardiologist if scarring were found.
My takeaway? Rethink the timing of races within 3-4 weeks of each other (maybe including the final race rehearsal before an Ironman?) IM: no closer than 4 weeks; race rehearsal: 3 weeks seems to be cutting it close; marathon and HIM: 2 weeks spearation. Also, next year, after this article has come out in print, I'll get a referral to a cardiologist and see if I can finagle a cardiac MI.
Still and all, I'm much more worried about prostate cancer and freeway crashes than I am about a deadly arrhythmia from too much exercise and racing. In the past 10-15 years, there have been 1000's of elite IM athletes training and racing. If this were a significant issue, we should have started hearing about it from doctors in Colorado, California, etc. Or, maybe this is the canary in the coal mine.
I do think and will say again that I believe that we need to take more time off after an endurance event not just space out the event but take time off from racing and training to allow our hearts to heal. For me currently that will be 2-3 weeks with no training only stretching following an endurance event and and no restarting of serious training for 4-6 weeks.
Bill sorry to hear of your issues. I hope all works out well for you.
Endurance Athletes May Incur Heart Damage
December 06, 2011
Intense endurance exercise -- such as running a marathon -- may induce cardiac damage confined to the right ventricle, a small study showed.
Highly trained endurance athletes had reductions in right ventricular function immediately after a race, although it mostly returned to normal about a week later, according to André La Gerche, MBBS, PhD, of the University of Melbourne in Australia, and colleagues.
However, a handful of the athletes had signs of subclinical myocardial scarring on cardiac MRI, "suggesting that repetitive ultra-endurance exercise may lead to more extensive right ventricular change and possible myocardial fibrosis," the researchers reported online in the European Heart Journal.
There were no changes in left ventricular function, which "provides further circumstantial evidence for the emerging concept that the right ventricle may be more susceptible to exercise-induced injury [than the left]," they wrote.
The study included 40 athletes (mean age 37) who were participating in a marathon, an endurance triathlon, an alpine cycling race, or an ultra triathlon. All trained for more than 10 hours a week and had finished in the top quarter of a recent endurance race. None had cardiac symptoms or risk factors.
The researchers evaluated the athletes two to three weeks before the race, immediately after the race, and six to 11 days after the race.
Compared with baseline, right ventricular volumes increased, and all measures of right ventricular function worsened immediately post race. Left ventricular function was unaffected.
Levels of two biomarkers of myocardial injury -- cardiac troponin I and B-type natriuretic peptide -- significantly increased following the race (P=0.003 for both). The changes were associated with reductions in right ventricular ejection fraction (P=0.002 for both), but were unrelated to left ventricular ejection fraction.
Lower right ventricular ejection fraction was significantly associated with longer race duration and increasing peak oxygen uptake (P=0.011 for both).
By six to 11 days after the race, most measures of right ventricular function had returned to normal, with the exception of right ventricular strain rates, which remained lower.
In the 39 athletes who underwent cardiac MRI, five had delayed gadolinium enhancement confined to the interventricular septum, indicative of subclinical myocardial fibrosis. These athletes had been competing in endurance sports longer and had lower right ventricular ejection fractions compared with those with normal MRI findings.
Because the study was not powered to assess clinical outcomes, the significance of the MRI findings requires further study, according to the authors.
The study "begs the hypothetical question whether repetitive longstanding bouts of arduous exercise result in the development of an acquired form of arrhythmogenic right ventricular cardiomyopathy," Sanjay Sharma, MD, and Abbas Zaidi, MBBS, of St. George's University of London, wrote in an accompanying editorial.
"The results provide food for thought and the data should be embraced to galvanize more detailed and longitudinal assessment of large groups of endurance athletes," they wrote. "The potential for such projects is enormous considering the colossal increase in participation rates in endurance events such as the marathon."
La Gerche is supported by a postgraduate scholarship from the National Health and Medical Research Council in Australia. The project was financed, in part, by a Cardiovascular Lipid Grant from Pfizer Australia.
The authors reported that they had no conflicts of interest.
The editorialists reported that they had no conflicts of interest.
Primary source: European Heart Journal
Source reference:
La Gerche A, et al "Exercise-induced right ventricular dysfunction and structural remodelling in endurance athletes" Eur Heart J 2011; DOI: 10.1093/eurheartj/ehr397.
Additional source: European Heart Journal
Source reference:
Sharma S, Zaidi A "Exercise-induced arrhythmogenic right ventricular cardiomyopathy: fact or fallacy?" Eur Heart J 2011; DOI: 10.1093/eurheartj/ehr436.
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another report on the study:
New research links endurance exercise to damage in the right ventricle of the heart
Embargoed: 00.05 hrs (GMT) Wednesday 7 December 2011
Researchers have found the first evidence that some athletes who take part in extreme endurance exercise such as marathons, endurance triathlons, alpine cycling or ultra triathlons may incur damage to the right ventricles of their hearts – one of the four chambers in the heart involved in pumping blood around the body.
The research, published online today in the European Heart Journal [1], found that although the damage was reversed within a week of a competitive event in most of the 40 athletes studied, five of them (13%) showed evidence of more permanent damage, with magnetic resonance imaging (MRI) showing scarring of the heart muscle (known as fibrosis). These five had been competing in endurance sports for longer than those who did not show the same damage.
Dr André La Gerche (MD, PhD), a postdoctoral research fellow at St Vincent’s Hospital, University of Melbourne, Australia, but who is currently based at the University Hospitals Leuven, Belgium, said: “It is most important that our findings are not over-extrapolated to infer that endurance exercise is unhealthy. Our data do not support this premise.”
However, he said that the findings did suggest that there might be some athletes who might have been born with a susceptibility to develop damage as a result of long-term endurance exercise.
“Virtually all of the changes in the athletes’ hearts had resolved one week after having taken part in a competitive event. In most athletes, a combination of sensible training and adequate recovery should cause an improvement in heart muscle function; that is, the heart rebuilds in a manner such that it is more capable of sustaining a similar exercise stimulus in the future. This positive training response can be over months rather than weeks,” he explained. “The question from our research is whether there are some athletes in whom extreme exercise may cause injury from which the heart does not recover completely. If this occurs, affected athletes may be at risk of reduced performance – a cardiac ‘over-training’ syndrome – or it may cause arrhythmias. If this occurs, it is likely to affect only a minority of athletes, particularly those in whom more intense training fails to result in further improvements in their performance.”
Dr La Gerche and his colleagues in Australia and Belgium recruited 40 elite athletes in Australia who were planning to compete in one of the four endurance events [2]. The athletes were already well trained (training intensely for more than 10 hours a week), performing well (having finished within the first 25% of the field in a recent event), and had no known heart problems.
The researchers studied the athletes, using echocardiography, MRI, and blood tests, at three time points: two to three weeks prior to the race, immediately after the race (within one hour), and 6-11 days after the race.
Results showed that immediately after the race the athletes’ hearts had changed shape, with the volume increasing, while the function of the ventricle decreased. Levels of a chemical called B-type natriuretic peptide (BNP), which is secreted by the ventricles in response to excessive stretching of heart muscle cells, increased. Right ventricle function recovered in most athletes after one week, but in the five who had been training and competing for longer than the others, MRI detected signs of scarring (fibrosis). The researchers also found that the post-race changes to the function of the right ventricle increased with the duration of the race.
In contrast, the left ventricle, which, up to now has been the most studied in athletes, showed no changes.
Dr La Gerche said: “Our study identifies the right ventricle as being most susceptible to exercise-induced injury and suggest that the right ventricle should be a focus of attention as we try to determine the clinical significance of these results. Large, prospective, multi-centre trials are required to elucidate whether extreme exercise may promote arrhythmias in some athletes. To draw an analogy, some tennis players develop tennis elbow. This does not mean that tennis is bad for you; rather it identifies an area of susceptibility on which to focus treatment and preventative measures.”
He concluded: “It is important to note that this is one component of an evolving understanding of how the right ventricle is the ‘Achilles heel’ of heart function during exercise. We previously studied heart function during intense exercise and demonstrated that the load on the right ventricle (stress, work and oxygen demand) increases to a greater extent than in any of the other heart chambers. Professor Hein Heidbuchel, who I work with, has shown that the source of ventricular arrhythmias in affected athletes is almost always the right ventricle. Finally, it has been shown that intense exercise in rats causes inflammation, fibrosis and arrhythmias in the right but not the left ventricle. Hence, there are consistent messages, all implicating the right ventricle and yet it has been neglected in the vast majority of studies regarding cardiac changes in athletes. Now there is sufficient evidence to invest in the long-term prospective studies that are required.”
In an accompanying editorial [3], Professor Sanjay Sharma, of St George’s University London (UK), who is medical director of the London Marathon, writes that although the study is small, “the results provide food for thought and the data should be embraced to galvanise more detailed and longitudinal assessment of large groups of endurance athletes. The potential for such projects is enormous considering the colossal increase in participation rates in endurance events such as the marathon. The long-term conclusions of the authors may appear preposterous to some, but could prove to be the retrospective ‘elephant in the room’.”
In a statement for this press release, Prof Sharma said: “My personal feeling is that extreme endurance exercise probably does cause damage to the heart in some athletes. I don’t believe that the human body is designed to exercise at full stretch for as long as 11 hours a day, so damage to the heart is not implausible. It is too early to say that taking part in endurance sports causes long-term damage to the right ventricle, but this study is an indication that it might cause a problem in some endurance athletes with a predisposition and, therefore, it should be studied further.”
(ends)
Authors: Contact: (media inquiries only):
Emma Mason
Mobile: +44(0)7711 296 986
Email: wordmason@mac.com
ESC Press & PR Office (for independent comment):
Tel: +33 (0)4 92 94 86 27.
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Notes to editor
The European Heart Journal is the flagship journal of the European Society of Cardiology. It is published on behalf of the ESC by Oxford Journals, a division of Oxford University Press. Please acknowledge the journal as a source in any articles.
[1] “Exercise induced right ventricular dysfunction and structural remodelling in endurance athletes”. European Heart Journal. doi:10.1093/eurheartj/ehr397
[2] The distances for each event are as follows: marathon = 42.2 kms; endurance triathlon = 1.9km swim, 90 kms cycle, 21.1 kms run; alpine cycling = 207 kms; ultra triathlon = 3.8 kms swim, 180 kms cycle, 42.2 kms run.
[3] “Exercise-induced arrhythmogenic right ventricular cardiomyopathy: fact or fallacy?”. European Heart Journal. doi:10.1093/eurheartj/ehr436
References Advance Access link for the European Heart Journal
Oxford University Press website
There have always been studies that people could point to if they want to avoid exercise...just add this one to the list. Need I mention that medical science as recent as the 1970's was justification for keeping women's olympic events to 3000m and less? And while the implications of this current research are extraordinarily serious, I don't believe the authors or the rest of medical science have a full understanding of the lasting impacts of intense or extended exercise (they differ). I can only agree with them that further longitudinal research is necessary. Meanwhile, having been a long distance runner for over 4 decades, I will lose no sleep over this. In fact, it's time for me to head out the door and run.
I think I'm echoing Jeff's sentiments below.
If I didn't have my endurance exercise and training, I would probably still weigh 350 lbs and be waisting my life away on the couch, or in front of a computer. I would rather my number be up when I'm doing something I love like running or cycling that to have it come up in front of the computer, or driving somewhere in a car.
I feel alive when I'm running and cycling.
@Paul I like your take on it. Hope you ha d agood run.
@Sam You only have one life, enjoy it and feel alive.
One thought on this: it might make sense for endurance athletes to take a "breather year" once in awhile, just like we take rest days in our training weeks, and light weeks in our training cycle for the year.
I tend to cycle through years where I do long distance HIM, marathon, or IM races, years where I do shorter distances like Oly's, sprints, and shorter running or cycling events, and the occasional year where I don't do any competing or just do a couple of small fun races. This last summer was planned as a no race year. I did some fun events (a 6.4 mile swim across Crater Lake with some friends, a 24 mile trail run with my hubby and BIL supporting me on mountain bikes) but neither of those was at anything approaching a race intensity. They were experiences, not races. Other experiences have included learning martial arts, being on a skydiving team, riding the Seattle To Portland, climbing Mt. Kilimanjaro. I know that in those kind of conditions, I don't push myself the way I do when I'm five miles from a finish line in a race situation.
I guess I'm saying that it doesn't have to be either/or - either I'm a couch potato or I do Ironmans every year. There are so many different things out there to experience and enjoy. Rotating through competitive times and less competitive times may indeed be better for our health (and heart) than pushing it to the limit year in and year out. This is just my n=1 with 25 years in the sport, still being competitive and still loving it.
All I know is I am one of those endurance athletes who developed Afib. To me, it was out of NOWHERE. I have ZERO other risk factors--no family history, no HBP, no diabetes, no ischemic heart disease, no structural deformity of the heart. It started when I was training for IMWI, coupled with a life-threatening cycling accident suffered by my husband. The docs feel the stress of BOTH was likely contributory.
I had parosysmal (lone) Afib, and had an ablation on 9/15. I have not had an episode since the ablation, but that doesn't mean it will never return. I may or may not be cured for good. Although every passing month the outlook gets better, although it can come back even years form now.
Trust me when I tell you, if you develop an arrythmia--and there is NO DOUBT that it is more prevelant in endurance athletes--it will change your life. And not for the better. I, literally, have scars on my heart from the procedure. I wish that on no one. I am getting back to training strong, but it is an uphill climb.
I signed up for IMFL, but am thinking long and hard about that. The docs are ambivalent. They really WANT me to exercise, and love the idea of running 5-6 miles and cycling a couple of hours. The rest? Well, they just don't have enough evidence yet, although a lot is pointing to the negative. They think these studies are, indeed, "the canary in the coal mine," but as we all know, it's complicated with much variabilit per the individual.
It's extremely difficult to turn away from the endurance triathlon, that much I know too.
I'm healthier for doing multisport stuff, bottom line. If my heart fibrillates or flutters, or I have that 'can't catch my breath' sensation (the one that's different than after the hard intervals), I back off. Otherwise, the way I see it, I only have so many grains of sand in the hourglass. And I have no idea as to how many there are or when they'll run out. So, I gotta go play, c ya!
I too am someone who had become sedentary before discovering a love for running and then tri. And yes, I find that working out and competing do make me feel alive.
However, out of respect for the Gleason family, can we please agree to discontinue use of the phrase "I'd rather die than...". Let's not forget Chris' constant admonition: this is all recreational athletics, it's just a game. Let's not take it too seriously.
Thank you.
Thanks for saying that Mike. I cringe whenever someone says something like "I'd rather die running, racing,whatever than infirmed in a bed or as a couch potato, blah, blah, blah." As if those are the only choices available. Life doesn't have to be extreme.
No offense to anyone who stated that in this thread (as I haven't read through it) but it's just a f**king stupid thing to say. Nobody would choose dying young in the pursuit of a hobby. EVER. It's ridiculous. There's isn't one damn person that says something like that and actually means it. Get some perspective, folks.
@Mike Excellent point and I hope no one is saying that. I've taken care only to be positive and make the statement that one has to enjoy their one and only life to the fullest. Triathlon is a major part of my enjoyment and I hope it continues to be.
I think if anyone did make a statement to that effect, it is likely something they said off the cuff and mostly b/c it is such an uncomfortable subject particularly with Chris' demise. I think there is an aura of invincibilty associated with high levels of fitness and it is hard for most of us to accept our mortality, kind of like when you were in your teens or 20's. Never thought about dying or death too much back then. In your 40's, 50's, etc....more in your mind. Not to mention dying slowly from a progessive, chronic ailment. That's unpleasant to think about and why many people say things like "I hope I have a heart attack in my sleep" or the like.
If anyone has made a statement to the effect of "I'd rather die racing..." I'm willing to avoid judging them b/c I feel they may be dealing w/ Chris' loss and perhaps their own issues in their own way but I also hope there are NO more posts to that effect.