Link fuzzy in study of mileage, lifespan

Dr. Martin Matsumura recently got a lesson in modern media: The slow march of science can't keep up with a hyper-connected society.

Matsumura, a cardiologist, recently presented to the American College of Cardiology the findings of a study looking at the health effects of running. Specifically, Matsumura and his colleagues wanted to find out why people who ran long distances for years had shorter lifespans than those who ran moderate distances.

The finding -- that there is a declining benefit to exercise at some point -- had been reached in a growing body of research, Matsumura said. He wanted to find out why.

But his presentation coincided with another report in Missouri Medicine linking super-long-distance running with more coronary artery plaque. A media onslaught occurred -- or at least what felt like an onslaught to a researcher whose work appears in highly technical medical journals.

"I was completely unprepared," he said.

News sites and television stations across the country picked up a health news service's report about his presentation and the Missouri report, and some outlets took it too far, said Matsumura, a doctor at Lehigh Valley Health Network in Pennsylvania. "It got overhyped a bit," he said.

The headline on one story he saw: "If you run too much, you won't live as long," Matsumura said. "And that's not exactly true."

Matsumura -- who is a runner and has competed in half-marathons -- said the correct story starts with the fundamental truth that exercise is good for all. However, studies in recent years, including research involving about 2,000 runners in the Copenhagen City Heart Study, have found that there is a point of diminishing returns for hard-core exercisers.

It appears that for runners, that line gets crossed after about 20 miles a week.

Matsumura suspected that the problem wasn't the additional hours of exercise, so he and his colleagues examined other reasons and posed the questions in a Web-based survey open to any runner 35 or older. Nearly 3,900 runners responded.

Did longer-distance runners take excessive amounts of pain relief drugs that, in large enough doses, can be damaging? (They actually found that shorter-distance runners consumed more, Matsumura said.)

Were they less conscientious about attending to their personal medical needs, thinking that the health effects of extra running balanced things out? (No, there was little difference.)

Matsumura said the researchers also asked about diet, coffee consumption and other factors.

The results didn't shed any more light on the issue. "We didn't have a good explanation for why longer-distance runners show less longevity," he said.

LESS IS MORE?

As for that longevity, the research team in the Copenhagen study found the increase in survival for runners vs. nonrunners was more than six years for male joggers and more than five for women.

In comparative terms, the study found that the relative risk of premature death was reduced by 44 percent for low-mileage runners, while the relative risk reduction was 14 percent for those running the highest mileage. But that still was better than the relative risk of nonrunners, Matsumura said.

Researchers will continue to follow runners in the coming years to see if they can determine the reason for the differences, he said.

As a runner, Matsumura knows better than to expect that other runners will slow down because of the research.

Neal Novak, president of the Lehigh Valley Roadrunners, agreed. "That report won't change their lifestyle one iota," he said.

A former marathoner who cut back to about 20 miles a week after undergoing hip surgery, Novak said runners run because they're "driven" people who find enjoyment in it.

"I don't know if it improves the quantity of your life, but it improves the quality of your life," he said.

That suits Matsumura, who does not advocate ending marathon runs. Instead, he says long-distance runners should keep up with the news.

If you're not a long distance runner, keeping the training in moderation is probably the right way to go, he said. "It is true if you're running purely for health, probably the 20-mile range is probably right."

ActiveStyle on 05/19/2014

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