Marathon participation has been growing swiftly over the last decade. Despite the increase in participants (including "ridiculously photogenic guy" 10k finisher to the right), mortality rate has not increased and average finish time has improved.
The marathon has seen tremendous growth in participation over the last decade. As the figure below shows, the number of marathon participants has soared from 299,000 participants in 2000 to 475,000 in 2009. This growth has been ruled in part by an increase in awareness of the benefits of running, many of which have been reported on this site. Despite the health benefits, one study found that 90% of marathon participants reported suffering a musculoskeletal or other participation-related injury prior to or during the marathon (Mortality Among Marathon Runners in the United States, 2000-2009. Published 2012. Simon C. Mathews, et al). In addition, the media has reported on several high-profile marathon deaths.
It might be supposed that given the increase in participants, mortality rate in marathon participants might rise due to a greater proportion of unqualified runners. A recent study found this not to be the case. In fact, not only have mortality rates remained constant over the last decade (as the figure below depicts), but average finish time has slightly decreased.
The rate of mortality remains slightly higher in males than females. The median age of mortality was 41.5 years old. The average distance completed before death was 22.5 miles. The most common cause of death among participants 45 years or older was myocardial infarction or coronary atherosclerosis (a heart attack). For younger participants the most common cause of death was cardiac arrest. Interestingly, participants who died within 24 hours of completing the marathon had an average finish time below the average of all marathon finishers. This suggests that physical fitness does not predict risk of marathon mortality, although it may be a sign of overexertion.
In conclusion, mortality rates in marathon finishers remains very low. Over the last decade there was 0.75 deaths per 100,000 finishers. By comparison, motor vehicle fatalities represent 11.2 deaths per a population of 100,000. Only 28 deaths of marathon participants during or in the 24 hours following their race have been reported in the last decade. This is an indication of the rarity of marathon fatalities, and also the limits of drawing demographic conclusions on the basis of such a small sample size. Marathon mortalities prevalence in the media is the result of several high profile incidents. Overall marathon running is safe regardless of age or physical fitness.