If running 15 miles a week is heart healthy, running 45 miles a week gives you a cardiovascular system three times as clean and strong, right?
A new study sounds a serious alarm about such thinking, adding to a growing body of research on the topic of excessive endurance exercise.
You’ve heard of runner’s high. Researchers now want you to hear about runner’s plaque — coronary artery plaque.
In short: Running super-long distances for many years might backfire on you.
“Years of extreme exercise efforts appear to erase some benefits you get from moderate exercise, so that your risk of heart disease, of dying of coronary disease, is the same as a sedentary person,” said Dr. James O’Keefe, preventive cardiologist at St. Luke’s Hospital in Kansas City, Mo.
O’Keefe said the study found men who were marathon runners for 25 years had 62 percent more plaque buildup in their coronary arteries than men who were sedentary but were similar to the runners in other respects, including age.
And the increased quantity of plaque in the marathoners’ arteries included both hard, or calcified, plaque and the more dangerous soft, fatty plaque. The latter is the kind that can be predisposed to rupture and cause a heart attack.
O’Keefe is co-author of the paper in the latest issue of Missouri Medicine, the journal of the Missouri State Medical Association. The study was conducted by Robert Schwartz and colleagues at the Minneapolis Heart Institute Foundation.
An unwavering advocate of exercise and its health benefits, O’Keefe said the new study adds weight to the idea that the potent benefits of exercise are “dose dependent.”
That is, the right amount matters. Being sedentary is unhealthy. Regular, moderate exercise bestows long-term benefits.
While logging huge numbers of miles and running marathons can keep you thinner, lower your risk for Type 2 diabetes and offer other benefits, it appears the subsequent wear and tear on the heart is a potential drawback, O’Keefe said.
The study’s marathoners, who had run at least one 26.2-mile race a year for 25 years, had a lower weight, resting heart rate and body mass index than the nonrunners. The average age of both groups was in the 50s.
That works out well for the 3-milers — keep doing that, O’Keefe said — but it’s cautionary news for marathoners and ultra-marathoners, at least those who have been at it for years.
Two years ago, in a report published in the journal Mayo Clinic Proceedings, O’Keefe and fellow authors cited evidence that extreme endurance training may cause structural damage to the heart, making it stiff and enlarged. That paper showed that moderate running distances two to five times a week at moderate speeds offered the best health benefits and that even 15 minutes a day of physical activity was helpful.
Eladio Valdez, coach of the Runner’s Edge training group in the Kansas City area, said he is aware of recent research about the potential ill effects of years of long-distance running. “I told my runners, ‘We can’t ignore this research,’” he said.
Running about 15 to 20 miles a week provides optimal health benefits, O’Keefe said. Or walking can provide benefits, from 2 miles a day to as much as 40 miles a week.
Virtually all types of exercise and activities also can be protective, but moderation is best for long-term benefits, he said.
“So this really knocks the props out from under anyone with the excuse ‘I just don’t have enough time’ or ‘I’ve never been an athlete,’” O’Keefe said. “You can train up to be the most ultra-fit endurance athlete ever, but that’s not what’s required for longevity. Moderate exercise is.”