Runners on path to longer lifetime.

It’s been a heck of a winter in my neck of the woods, with repetitive bouts of extreme cold, extreme snow and extreme ice. But through it all, runners have kept running, even when other Canadians were running for cover.

What motivates runners to lace up their shoes in conditions not fit for man or beast? Maybe they know intuitively what a group of American researchers finally put on paper.

“We found that runners had a 3.2 years longer life expectancy, compared with non-runners,” said researchers in an article titled Running as a Key Lifestyle Medicine for Longevity, published in Progress in Cardiovascular Diseases.

Reporting that runners have a 25 to 40 per cent reduced risk of premature mortality, the researchers — who hail from Harvard Medical School, Iowa State University, Hartford Hospital, University of South Carolina and University of Queensland School of Medicine — noted that running protects against cardiovascular disease and cancer, two leading causes of death in developed countries.

If you pull on a bathing suit every day instead of a pair of running shoes, you’re probably asking how this boost in longevity from running compares to swimming laps, among other forms of exercise.

First, it’s worth noting that regular bouts of any type of physical activity will reduce your risk of death. A sedentary lifestyle accounts for nine per cent of all-cause mortality worldwide and is considered the No. 4 risk factor for premature death, with high blood pressure, cigarette smoking and high blood glucose ranking one through three respectively.

Yet given roughly the same amount of physical activity, the risk of an early death was reduced by 27 per cent among runners who didn’t do any other type of exercise, versus a 12 per cent reduction in mortality among exercisers who didn’t run.

Clearly, running isn’t the only workout that helps you stay healthier longer. But there is a suggestion that it’s one of the more efficient means of warding off premature death, especially when compared to something like walking. According to the researchers’ calculations, it takes 15 to 105 minutes of walking to reap the same mortality-reduction benefits achieved from five to 25 minutes of running.

“This notable finding confirms that running is more time-efficient and could therefore be a better choice for busy yet healthy individuals,” said the researchers.

Before runners rise up in celebration, longevity benefits are at their best among those who run throughout their lives. Running participation declines by five to 10 per cent each decade after the age of 30, with less than two per cent of runners still at it past the age of 65.

As great as running is for keeping maladies at bay, some studies have suggested there’s a threshold after which running can actually increase the risk of death. Hence the advice that too much running isn’t good for your health. But not all studies support the idea that long distances on the run can undo the benefits acquired through a more moderate habit.

“Our study, with the largest sample size of over 55,000 adults, demonstrated no increased risk of all-cause and cardiovascular disease mortality even in the highest running group (4.5 or more hours per week) compared to the light running group (less than 51 minutes per week),” said the American researchers. “This was consistent in men, women, young and old individuals and slow and fast runners.”

So while there’s still debate about whether too much running can have a negative impact on longevity, most experts agree adding more miles to an already consistent running habit doesn’t necessarily mean subtracting years from your life.

Keep in mind, too, that the researchers viewed running volume based solely on how it affects premature death. There are other outcomes related to high volumes of running, including overuse injuries, which should be taken into consideration before bumping up your weekly mileage.

As for claims that running is tough on the knees, there’s a substantial body of evidence proving that arthritis is less common in runners than in the sedentary population.

Just remember that the benefits of running are greater for those who make it a lifelong habit. It pays to keep at it even when your pace begins to slow and your stride isn’t as crisp. It could be argued that those late-in-life runs have more impact on your health than the speedy runs of your youth, but it’s clear that exercise is medicine at any age.

“Running may be the most costeffective lifestyle medicine from (a) public health perspective,” said the American researchers.