WASHINGTON (WNEW) – Going for runs on a regular basis has been linked to a multitude of health benefits in countless research studies, but recent research suggests that too much running is tied to a shorter lifespan.
The study results revealed on Sunday by Dr. Martin Matsumura, co-director of the Cardiovascular Research Institute at the Lehigh Valley Health Network, found that people who get no exercise along with people considered high-mileage runners both have shorter lifespans than those considered to be running an average amount – although the researchers note that the reasons are still somewhat unclear.
"Our study didn't find any differences that could explain these longevity differences," said Dr. Martin Matsumura, CBS News reports. "What we still don't understand is defining the optimal dose of running for health and longevity."
Dr. Matsumura and his colleagues reviewed datafrom over 3,800 male and female runners who participated in the Masters Running Study, a web-based study of health and training for runners over the age of 35. Nearly 70 percent of the runners self-reported running more than 20 miles each week, and the average of the of the high-mileage runners was 42 years of age.
Information regarding use of painkillers and prescription medicines were compiled with heart risk factors, diabetes, high blood pressure and family history of chronic illness.
But the study authors said none of these factors explained the shorter lifespans associated with high-mileage runners versus moderate runners. And use of painkillers was actually more common among average runners.
Dr. James O'Keefe, director of preventive cardiology at the Mid-American Heart Institute in Kansas City, said that although the health risk factors still don't explain high-mileage runners' shorter longevity, excessive amounts of running were still potentially related to life-shortening effects.
He said there may simply be "too much wear and tear," CBS News reports. He said the "sweet spot" for running is a slow to moderate pace for a total of about 2.5 hours each week – about two to three times each week.
"I certainly don't tell patients 'Don't run,' " Matsumura told CBS. But O'Keefe added that "if you want to run a marathon, run one and cross it off your bucket list" as the lifespan-mileage link is subject to continued research.