Sigh. Is marathon running bad for your blah blah blah

I had originally decided that I couldn't be arsed posting this, but I saw a recent post in Outside magazine titled The Runner's Ticking Time: Why Runner's Need to Pay More Attention to Their Hearts which got my ire up again. Ignoring for a start the fact that one of the expert opinions that they quote is a registered dietician "who appears regularly on Good Morning America" (although at least dieticians are actually accredited, unlike nutritionists), the article is about the apparently high levels of heart attacks due to coronary artery disease that are seen in marathon runners. They even quote a paper from the Journal of the American College of Cardiology which says that "one in 50,000 will experience a heart attack from coronary artery disease during a marathon". Scary. Except that they miss out the kind of crucial (I think anyway) point that this is an incredibly small risk as compared to that of the general population. Here is the conclusion from the abstract in full:

Although highly trained athletes such as marathon runners may harbor underlying and potentially lethal cardiovascular disease, the risk for sudden cardiac death associated with such intense physical effort was exceedingly small (1 in 50,000) and as little as 1/100th of the annual overall risk associated with living, either with or without heart disease. The low risk for sudden death identified in long-distance runners from the general population suggests that routine screening for cardiovascular disease in such athletic populations may not be justifiable.

Is marathon running bad for your heart? Sigh...

I spotted a news story on the BBC News website this morning which claims that Marathon training 'may pose a heart risk'. This story has since caused a bit of a buzz on the interwebs, cropping up in various tabloids and on various discussion forums and blogs. Being a runner and a scientist, this of course piqued my interest. Is this something that I should be concerned about, or is this another case of sensationalism by the media? Take a guess...

First things first. The study in question is a paper published yesterday (6th December 2011) in the European Heart Journal by a group in Belgium entitled  "Exercise-induced right ventricular dysfunction and structural remodelling in endurance athletes". Unfortunately, it requires a subscription, but you can see the abstract here. Being a scientist myself, I have looked over the paper and thought that I would share my thoughts on the implications.

The study measures various aspects of cardiac function for 40 endurance athletes, each a specialist in one of 4 events which are, in order of duration; marathon, endurance triathlon (possibly Olympic length?), alpine cycling, or ultra-triathlon (Ironman distance). Measurements of cardiac function were taken using cardiac magnetic resonance imaging (cMRI) and echocardiograms, as well as analysis of biochemical markers of function such as B-type natriuretic peptide (BNP) and cardiac troponin I (cTnI), both proteins involved with contractions of muscle cells in the heart and hence good predictors of cardiac risk. For each athlete, three measurements were taken; the first was taken as a baseline 2-3 weeks prior to the event, the second was taken within an hour of crossing the finishing line at the event, and the final 'delayed' measurement was taken 6-11 days after the event.

Broadly speaking, they found the following key results:

Loch Ness Marathon - October 2011

The past few weeks since the Grafham Water marathon have been a bit of a bust in terms of training. I have just about managed to squeeze about 20 miles in, but other than that it has been a run free zone. In my defence, this is due to my recent nuptuals. Yes, I am now a married man (sorry girls...). And how are we spending our first weekend together as man and wife? Well I've buggered off up to Loch Ness, and Jen's getting drunk with her friends! Ah, marriage!

Dan Park, Pete Lefort and I woke up on Saturday bright and early, ready to hit the road at 5am. We were expecting a good 9 or so hours drive up to Inverness, so Dan and I shared the driving, with Pete being in charge of the games of I Spy.

When the sun came up it was clear it was going to be another beautiful day - in fact, it ended up being the hottest day in October for a very long time. Well, in Cambridge at least. As soon as we hit Scotland, the heavens opened and the world turned dark and dank. We spent the day getting very wet, and eating our lunch in the rain. By all accounts, a perfectly typical summer's day out in Scotland...

Dan and Pete sightseeing in Scotland.