Is Running Dangerous?

January 10th, 2013 by Andrea Bennett

A number of new studies examine whether running marathons is dangerous, or not statistically worse than any other activity.

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Running has been in the news lately, and not for its health benefits.

Rather, a number of new studies suggest that endurance training and marathon running can literally push your heart to its limit. Yahoo! Health writer Lisa Collier Cool notes that a new study from the British journal Heart blames running for a variety of problems, such as arrhythmia or irregular heartbeat, as well as lasting damage like calcification and scarring.

In a 2012 Mayo Clinic study, Cool notes, researchers associated endurance training with spikes in sustained inflammation that could injure the heart muscle, and impairing the muscle could lead to arrhythmia or sudden death, which is what killed runner Micah True last year while running a marathon in Mexico.

But, as Gretchen Reynolds asks in a New York Times piece on the topic, “Shouldn’t marathon training have made [True] – and, by extension, all runners – immune to heart disease?” The answer appears to be, she notes, “that, over all, distance running and racing are extremely unlikely to kill you – except when, in rare instances, they do.” 

The newest study, recently published in The American Journal of Sports Medicine by researchers at Johns Hopkins University School of Medicine, tracked data on deaths during or immediately after every marathon race in the United States from 2000 to 2009. Even as participation in marathon racing nearly doubled in almost 10 years from 299,000 to 473,00, the death rate remained unchanged, with a total of 28 people dying during or in the hours right after a marathon, primarily of heart problems (or less than one person in 100,000 over all). As lead author of the study, Dr. Julius Cuong Pam, an associate professor of emergency medicine, told Reynolds, “Our data shows, quite strongly, that marathon running is safe for the vast majority of runners,” and he suspected that many runners had actually been spared from a heart attack that would otherwise have been brought on by a sedentary lifestyle. 

Indeed, training may be the key to staving off the risks of overdoing it, Cool suggests. A 2010 study presented at the Canadian Cardiovascular Congress showed that runners who were less fit had signs of inflammation and swelling, while runners who were better trained over a longer period were less likely to experience the same degree of heart damage. 

How do you regard studies like these? Does reading results that suggest running is dangerous make you less likely to exercise or more likely to simply believe that nearly anything should be enjoyed in moderation – exercise included? Weigh in.