The 2009 death rate of about 0.75 per 100,000 race finishers is comparable to the rate a decade earlier, researchers say. Men, however, were twice as likely to die as women. “It’s very dramatic when someone dies on the course, but it’s not common,” says Julius Cuong Pham, associate professor of emergency medicine and anesthesiology/critical care medicine at the Johns Hopkins University. “There are clearly many health benefits associated with running,” says Pham, who led a study published online in the American Journal of Sports Medicine. “It doesn’t make you immune, but your risk of dying from running a marathon is very, very low.” Pham and his colleagues found that between 2000 and 2009, 28 people died during or in the 24 hours following a marathon, most of them men. Half of those who died were over age 45, and all but one in the over-45 group died of heart disease. For younger runners, the causes of death varied widely and included cardiac arrhythmia and hyponatremia, the latter owing to drinking excessive amounts of water. Marathon running has long been considered the pinnacle of endurance athletic events, but the 26.2-mile road races have become even more popular in recent years. Pham and colleagues looked at statistics from approximately 300 marathons per year and found that the number of finishers increased 58 percent between 2000 and 2009, from 299,018 to 473,354. The researchers say they believe the spiking marathon participation reflects, in part, increased awareness of the health benefits gained from regular exercise. Numerous studies have linked exercise to better physical and mental health, and to longevity, Pham says. Similarly, marathon running has been associated with decreased risks of hypertension, high cholesterol, and diabetes. People who run regularly have been found to have lower rates of all-cause mortality and disability. No one should conclude, however, that marathon training or running is risk-free, says Pham, a three-time marathoner himself. He notes that studies have shown the yearly incidence of injury in people training for marathons to be as high as 90 percent, with the vast majority of injuries damaging the musculoskeletal system.