Running Is Good—But Not for Too Long or Too Far

A new report argues that working out for too long can take years off your life.

An editorial published by two cardiologists in Heart argues that running is good for health, but too much of it can be detrimental and sometimes life-threatening. Photograph courtesy of Shutterstock.

We’ve heard the quotes before: “Running is medicine.” “Running is your sport’s punishment.”

To fitness enthusiasts and athletes alike, running is the end-all, be-all. It’s what many athletes do to warm up, train, and cool down. It’s how 9-to-5ers start their day, with a brisk jog through neighboring streets. To many, running is a way of life.

A recent editorial published in the journal Heart by the BMJ Group, however, delves into the question that can’t seem to find a definitive answer: Is there such a thing as too much running?

Talk to any avid marathon runner or triathlete, and they’ll likely—and proudly—say, “No.” But the authors of the editorial, Dr. James H. O’Keefe and Dr. Carl J. Lavie, both cardiologists, argue otherwise, citing some pretty damning evidence that running for too long and too far causes excessive damage to our hearts.

Take the case of Micah True. The American known to readers of Born to Run as Caballo Blanco became famous for his ability to run 25 to 100 miles in one go routinely. In March this year, he was found dead days after going for one of his long runs in New Mexico. O’Keefe and Lavie note that according to biopsy results, True suffered from an enlarged and thickened heart: “The coronary arteries were ‘focally thickened with mild coronary arteriosclerosis,’” they wrote—symptoms that have been observed in other extreme endurance athletes, as well. 

When one exercises at a strenuous pace, the heart works five to seven times harder than at rest, pumping up to 25 to 35 liters of blood a minute. The good news is that our hearts can handle the hard work. They struggle, however, when they work at this pace on a regular basis, eventually causing heart tearing and, in some very rare cases, death.

While it’s true that the odds of dying from a marathon are extremely low—0.75 per 100,000—the doctors argue that the dangers arise when your weekly mileage exceeds a certain number. They cite a recent study that found that runners in general are 19 percent more likely to live longer than non-runners. However, those who ran about 25 miles per week appeared to lose their advantage, while 5-to-20-mile runners had a 25 percent increase of longevity. 

Other studies have found that exercising daily for about 30 to 45 minutes is ideal; working out for more than 45 minutes provides no added benefits to one’s health.

So what’s a well-meaning marathon runner or triathlete to do? Well, not much, apparently, except continue eating and training smartly—and, of course, to consult your doctor if you have a history of heart problems. “If one really wants to do a marathon or full-distance triathlon, it may be best to do just one or a few and then proceed to safer and healthier exercise patterns,” they wrote.

For the rest of us, O’Keefe and Lavie have some other advice: “The take home message for most is to limit one’s vigorous exercise to 30 to 50 minutes a day. [. . .] A routine of moderate physical activity will add life to your years, as well as years to your life.”

“On the other hand,” they continue, “running too fast, too far, and for too many years may speed one’s progress towards the finish line of life.”

The full editorial is available on BMJ’s website