Running too much may lead to shorter lifespan: study

High-mileage runners and those who get no exercise may lead shorter lives compared to moderate runners, a new study suggests.

Running is linked to all sorts of health benefits -- weight control, stress reduction, better blood pressure and cholesterol, for example -- but there is such a thing as too much of a good thing, researchers say.

A "moderate" running regimen, which is about two to three hours per week, yields longevity and optimal health benefits, though the reasons for the discrepancy are still unclear.

"Our study didn't find any differences that could explain these longevity differences," Dr. Martin Matsumura, co-director of the Cardiovascular Research Institute at the Lehigh Valley Health Network in Allentown, Pa., said in a HealthDay report.

Matsumura and his colleagues evaluated data from more than 3,800 men and women runners age 35 and above. Almost 70 percent reported running more than 20 miles a week.

The runners supplied information on their use of common painkillers called NSAIDs (nonsteroidal anti-inflammatory medications) -- ibuprofen and Aleve included, which have been linked with heart problems, as well as aspirin, known to be heart-protective. Participants in the web-based Masters Running Study also reported any known heart risk factors such as high blood pressure, high cholesterol and diabetes.

Taking this into account, the study seems to rule out cardiac risk or the use of certain medications as factors related to the decreased longevity.

Dr. James O'Keefe, director of preventive cardiology at the Mid-American Heart Institute in Kansas City, reviewed the study and speculated that high-mileage running simply causes "too much wear and tear" on the body. It's possible the heart "remodels" itself when subjected to chronic extreme exercise, undermining running's benefits.

"I certainly don't tell patients 'Don't run,'" Matsumura said. But, "What we still don't understand is defining the optimal dose of running for health and longevity," he added.

O'Keefe advises runners to avoid strenuous exercise for more than an hour at a time.

Running is linked to all sorts of health benefits -- weight control, stress reduction, better blood pressure and cholesterol, for example -- but there is such a thing as too much of a good thing, researchers say.

A "moderate" running regimen, which is about two to three hours per week, yields longevity and optimal health benefits, though the reasons for the discrepancy are still unclear.

"Our study didn't find any differences that could explain these longevity differences," Dr. Martin Matsumura, co-director of the Cardiovascular Research Institute at the Lehigh Valley Health Network in Allentown, Pa., said in a HealthDay report.

Matsumura and his colleagues evaluated data from more than 3,800 men and women runners age 35 and above. Almost 70 percent reported running more than 20 miles a week.

The runners supplied information on their use of common painkillers called NSAIDs (nonsteroidal anti-inflammatory medications) -- ibuprofen and Aleve included, which have been linked with heart problems, as well as aspirin, known to be heart-protective. Participants in the web-based Masters Running Study also reported any known heart risk factors such as high blood pressure, high cholesterol and diabetes.

Taking this into account, the study seems to rule out cardiac risk or the use of certain medications as factors related to the decreased longevity.

Dr. James O'Keefe, director of preventive cardiology at the Mid-American Heart Institute in Kansas City, reviewed the study and speculated that high-mileage running simply causes "too much wear and tear" on the body. It's possible the heart "remodels" itself when subjected to chronic extreme exercise, undermining running's benefits.

"I certainly don't tell patients 'Don't run,'" Matsumura said. But, "What we still don't understand is defining the optimal dose of running for health and longevity," he added.

O'Keefe advises runners to avoid strenuous exercise for more than an hour at a time.