Marathon running appears to ‘damage the heart’

While aerobic exercise such as walking, running and cycling appears not to be great for weight loss, I am enthusiastic about it for likely benefits for both body and brain. But there are limits. While exercise may be broadly healthy, more is not necessarily better. For example, practically every amateur runner I have ever met who has run a marathon (26.2 miles/42 km) has admitted to one or more ‘overuse injuries’ associated with the training for the event or running of it. One of my best friends ran his one and only marathon while still a competitive triathlete and was laid low in a persistent infection for several weeks after the run (prolonged exercise can suppress the immune system).

I am not against marathon running, but I don’t have much enthusiasm for it either. I’ve always believed the training required as well as the event itself is simply too arduous for most mere mortals. This is one reason why I’ve never run one myself, despite being a keen runner on and off until my early 30s. The thing that eventually convinced me to stop distance running was, by the way, needing to spend increasing amounts of time on the osteopaths couch having misalignments of my body seemingly induced by running manipulated out of me. This, despite wearing the ‘right’ shoes and having a pretty fluid running style.

The idea that long distance running may not be such a good idea came back to me today when I read about a study today which was presented recently at the Canadian Cardiovascular Congress.

In this study, led by Dr Eric Larose at the University of Laval, Quebec City, Canada, 20 amateur runners had their heart function assessed 6-8 weeks before running a marathon, as well as two days and then three months later. The function of the heart was assessed with MRI scanning. The participants also had their fitness assessed (VO2 max).

Two days after the marathon, there was evidence of damage to the heart muscle in the form of inflammation, swelling and ‘decreased perfusion’ (reduced blood supply) to parts of the left ventricle (the heart’s main chamber responsible for pumping blood to the body’s tissues). From the report I read, it seems that at least some of these changes were observed in at least some runners 3 months after the run too.

Perhaps not surprisingly, the fitter runners were less likely to show the signs of damage to the heart described here.

Apparently, Dr Larose was interested to know how it can be that someone who is apparently healthy enough to run a marathon can suddenly drop dead. Dr Larose’s take on this is that we should not assume there is no risk to the heart in marathon runners. He is quoted as saying “To sweep this under the rug and say, they’re marathoners, they’re good, is no okay.”

Let’s not over-interpret this: In real terms, the risk of dying from running a marathon is very small. However, what this study appears to show is that running a marathon puts significant stress and strain on the heart that can damage it, and that damage appears to last (for some people, at least) for quite a while after the event.

Part of my enthusiasm for running came as a result of reading the book ‘The Complete Book of Running’ by American amateur runner Jim Fixx. I was given the book by my parents for Christmas in 1981. I still have this book on the bookshelf in my office at home.

Jim Fixx was credited with helping to start the running boom in the 1980s. In 1984 Jim Fixx died of a heart attack, while out running. He was previously overweight and a smoker. These things may well have played a part in his demise. However, this latest evidence suggests that the distance running might have been a factor too.

I’d encourage practically anyone to take regular aerobic exercise. I don’t remember once suggesting that someone should aim their sights on a marathon. Of course there is a challenge with completing this epic distance, but the reality is being fit and healthy takes much less time and effort, and maybe better and safer for the body too.

10 Responses to Marathon running appears to ‘damage the heart’

  1. Chris Highcock 2 November 2010 at 12:00 am #

    This isn’t just theory, people die doing marathons

  2. Tuck 2 November 2010 at 12:53 am #

    I’m curious then to see your reaction to this study:

    To my amateur eye, it doesn’t seem to show any long-term ill effects from running, quite the contrary, in fact.

  3. John Briffa 2 November 2010 at 1:23 am #


    The study you link to is epidemiological in nature, and it’s therefore difficult to draw any conclusions about its results.

    The piece above is primarily about marathon running. The study you link to does not seem to distinguish between differnet intensities or durations of running.

    There is some evidence linking marathon running to a small increase in the risk of sudden, cardiac-related death. See here for instance.

  4. Barry 2 November 2010 at 2:53 pm #

    so how come this guy hasn’t keeled over ??

    Inflammation is the precursor for adaptation. Its how we get fitter !

    I think this post is another example of what works for some, doesn’t work for others. Frankly, I don’t think it has much value. It is like reporting that nuts can cause cardiac arrest. Yes for some, but they have health benefits for others.

  5. John Briffa 2 November 2010 at 3:09 pm #


    I think this post is another example of what works for some, doesn’t work for others.

    You could say that about practically anything. Do you have particular issue in the highlighting of an issue which appears to be real but gets, generally, little or no attention?

  6. Barry 2 November 2010 at 11:20 pm #


    I have no problem with highlighting “real” issues that get no attention. However, this particular topic has just got too many holes in it to lead to any sort of a conclusion. To qoute yourself:
    “From the report I read, it seems that at least some of these changes were observed in at least some runners 3 months after the run too.”

    so what exactly were these changes and were they significant ? The report says marathon running causes “inflammation”… any strenous exercise causes inflammation.. it is the the whole process by which the body adapts. Had they looked at the same parameters of the same subjects after they had ran several more marathons.. I think you would see a very different set of results.

    Of course an event such as a marathon can be damaging to the untrained (or even trained individual with a rare condition)… but thats the same with everything ! Trying to swim the English Channel without swimming a few lengths of the pool first could be “damaging”… Squatting 200lbs first without first lifting smaller weights could be “damaging”…

    So this is 1 study, on 1 set of runners, after 1 marathon.. with testing not going further than 3 months… hardly worthy of coming to the conclusion that “marathon running appears to damage the heart” ??

  7. John Briffa 2 November 2010 at 11:30 pm #


    hardly worthy of coming to the conclusion that “marathon running appears to damage the heart” ??

    Except, of course, that’s exactly what this research appears to demonstrate…

  8. Joseph Putnoki 6 November 2010 at 9:54 am #

    Dr Briffa,
    you deserve that I share some of my knowledge and alert you to the website below:
    Dr Sears PACE Program – Just What Do People Really Think?
    Both of you create the synergy and add details to the tapestry of health, exercise and nutrition. The program is revolutionary and the website I mention is not primarily weight reduction. it is only one welcome side issue. The topic of fitness and exercise became over-commercialized and Dr Sears found to be incorrect with serious consequences. Sports also highly commercialized the athletes pay a very high price in injury and premature death. The P.A.C.E. program sounds counterintuitive until you grasp the idea backed by evidence and explanation. Conventional training does not makes us healthy, shrinks our lungs and hearts and it was found recently that the most reliable predictor of early death is the level of lung capacity. The issue of inflammation at the end of exercise, is well explained. The system is empowering and affordable and lifesaving. Check it out!

    Be well!



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