Just How Safe is Running a Marathon?
By Elliott Gorelick
Staff Wrier
Imagine a clinical case presentation consisting of the following: The patient complains of fatigue and myalgia. In addition, there is dyspnea, diaphoresis and dehydration. Over the previous hours heart rate has been sustained above 150 bpm and systolic blood pressure over 200 mmHg. The patient has depleted 100% of their stored liver glycogen and may have electrolyte imbalances. A blood draw shows clinically significant levels of cardiac enzymes. The question is, do you think this is a benign, urgent or emergent situation? (“But wait, there’s more.”) This is all the culmination of deliberate multi-month plan by the patient. Do you want to add a psych consult to your mental checklist?
The scenario above happens over one million times per year in the United States with men and women of all ages and abilities competing in half-marathons and marathons. On Sunday, November 8, I will add myself to that group, but with some trepidation. This fall has been especially deadly with seven distance runners dying in the space of five weeks, starting on September 6 in Virginia Beach when a 23 -year-old collapsed during a half-marathon and continuing to October 18 in Detroit when three men collapsed and died within 20 minutes; in between, two people (including the only female) died in San Jose on October 4 and one in Baltimore on October 10. This is unprecedented and seems to contradict empirical evidence that running is safe. A 2007 study (Competing risks of mortality with marathons: retrospective analysis -2007) reviewing all deaths at major marathon events estimated the rate at 0.8 per 100,000 runners. This study actually concluded that there was a net decrease in overall mortality due to a reduction in traffic accidents because of road closures and detours. Earlier studies from the 1990’s concluded that the risk of death is about 1 in 50,000.
On the other hand, a spate of recent studies published over the last two years has shown that markers for cardiac damage are significantly elevated in almost all finishers of these races. Even those runners who have considerable experience in long distance running, show biomarkers of damage over half the time (Myocardial function in older male amateur marathon runners: assessment by tissue Doppler echocardiography, speckle tracking, and cardiac biomarkers-2009).
Is it safe? The answer in absolute terms is probably not. If you have no underlying hidden heart condition, then the risk is very, very low despite the disseminated muscle damage that mirrors the clinical signs of a minor heart attack.
On the other hand, there is no cost-effective way to know if you have hidden heart disease (nor even what the actual relative risk was if you did; they only autopsy the runners who die – there is no control group). What study after study has shown is that regular aerobic exercise improves overall health outcomes. For me, the benefits in terms of controlling my weight, keeping my blood sugar under control and lowering my blood pressure outweigh the risk. I suppose that one could gain all those benefits by training for the marathon without actually running it but then what would be the point? People run marathons to prove they can. I will never climb Everest (about one death per 10 successful attempts), but I can challenge myself with a lot easier, cheaper and safer goal.
This article appeared in the November 5, 2009 issue of Synapse.
