I’m not a big fan of studies of runners who drop dead, not because the topic scares me or doesn’t interest me, but because it’s so difficult to calibrate the message properly. When you write a post about the man who bites the dog, it doesn’t matter how many nuances and caveats you put in it: some people will inevitably come away feeling like it’s only a matter of time. before a mad human bites their beagle.
So let me make it clear at the outset that what follows is mostly good news. In the British Journal of Sports Medicine, a large team of researchers in Britain led by Charles Pedlar of St. Mary’s University published an analysis of every medical encounter at Parkrun events in the UK between 2014 and 2019. More than two million people there participated, totaling 29 million finishes, and 18 of them died. Each of these deaths is extremely sad, but the overall picture is encouraging nonetheless.
The Parkrun phenomenon, if you haven’t encountered it yet, is truly remarkable. Outside columnist Martin Fritz Huber wrote a column about this a few years ago (just like me, about my first Parkrun experience). The scheme is quite simple: every Saturday morning in communities around the world, volunteers organize a free and timed 5 km race. There are many theories and an emerging body of academic research seeking to explain why this is different from the ubiquitous community fun races that already exist. The lack of a registration fee helps, as does the fact that it happens every week rather than being an annual event. For some reason, last year seven million people were registered in 22 countries, with around 350,000 people participating each week. It’s huge.
With so many people, even very low probability events become a matter of when rather than if. In 2014, Parkrun implemented a mandatory system for reporting any medical problem encountered during each event. (The ultimate incentive to get organizers to comply: No finisher scores could be posted until they were received.) This is the database that Pedlar and his colleagues scoured.
There were a total of 84 serious incidents classified as life threatening, of which 73 involved the heart (48 cases of cardiac arrest, that is, when the heart stops; 20 cases of coronary syndrome acute, which includes heart attacks and other blockages in the blood supply to the heart and five severe arrhythmias). The others were stroke (eight), respiratory failure (two), and spinal injury (one). There were 7,492 other less serious medical events, most of which involved falls or crashes, and only 698 of which required a trip to the hospital.
So what’s the good news? Of the runners who suffered cardiac arrest, 65% survived. That’s far more than the ten percent who typically survive cardiac arrest when it happens outside of a hospital. The reason: All Parkrun events in the UK must have an automatic defibrillator on hand. One of the potential barriers to expanding free events like Parkrun is the issue of accountability and the need for more extensive medical support. But what makes Parkrun scalable is that it can be donned week after week by a small handful of volunteers with a few cones and a smartphone to scan barcodes at the finish line. This analysis suggests that even without medical personnel in the race crew, having a defibrillator is sufficient to significantly reduce the risk of death.
It is well established that just one session of vigorous exercise, such as running a 5 km, but also shoveling snow or even having sex, temporarily increases your risk of heart attack, but regular exercise lowers your risk. long term. You can see this tradeoff in action in the results. Here is, for example, a graph that shows how many previous Parkruns have been performed by people with a serious medical event:
Those who survived (top) tended to have completed many more previous races than those who did not (bottom). Likewise, fatal cases tended to end more slowly, which may indicate less prior training. The vast majority of serious incidents, both fatal and non-fatal, occurred in men (82%) who were over 45 (83%). None of this is surprising, but the authors suggest that it might be worth considering targeted educational material, or maybe even pre-participation online screening, for older, slower novice runners – an approach that reduced overall medical encounters by 29% in the Two Oceans Half Marathon and Ultramarathon in South Africa.
Still, it’s worth keeping the results in context. In the Two Oceans race, online screening and education reduced the rate of life-threatening medical events from 56 per 100,000 runners to 21. For the much shorter Parkruns, held in the temperate climate of Britain the rate was only 0.3 per 100,000. This is not much different from the rate of 0.8 sudden cardiac death per 100,000 seen in a study of three million runners. of marathon in 2007. The notable detail of this study: hospital admission data showed that for every sudden cardiac death during a marathon, two cars – accidental deaths were avoided thanks to street closures during the race. It is the comparison which deserves to be recalled. Yes, running is dangerous, but not as dangerous as not running.
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