For a long time now, the media has played on the fact that an endurance athlete will drop dead during or shortly after an extreme endurance event such as a half marathon, marathon, triathlon or ultra-marathon. While it’s the medias job to sell headlines, a basic dose of statistics will clear this up. Maron et al 1996 analyzed the runners over a 30 year period in the Marine Corps marathon and the Twin Cities marathon. Of 215,413 runners 4 deaths occurred during or shortly after the race. Straight up math, that’s 1.85 x10^-5 or 0.00185%! Now, it’s possible that the weather conditions and population demographics played a role in that percentage. So let’s take a look at some other studies. Pedoe and Tunstall 2007 looked at 25 years of London marathon data. They found 11 cardiac events with 8 deaths. They reported the estimated rate of death from cardiac event via marathon was 1 in 80,000 or 0.00125%- not too far from Maron’s study.
Essentially, if you do not have a heart defect or a poor hearth health profile (as determined by a heart scan and a cardiologist), and you are healthy- you can run a marathon with the proper training. If you have not trained for it- your heart will act the way your back would act when you try to lift a car. Keep the weather conditions in mind; as hydration, carbohydrate metabolism and fatty acid metabolism will all play a role. If you are at risk for cardiac events, it may be better to stick to the 5-10km range.