By Jonathan Lambert
If you’re looking for motivation to take up running, perhaps this will help. A new study finds that people who run as little as once a week have a lower risk of early death compared with people who don’t run at all.
In fact, any amount of running was associated with a 27 percent lower risk of premature death. And researchers found no evidence that running more alters that number significantly, according to a new meta-analysis published November 4 in the British Journal of Sports Medicine.
“This is good news for the many adults who find it hard to find time for exercise,” says Elaine Murtagh, an exercise physiologist at Mary Immaculate College in Limerick, Ireland, who was not involved in the study. “Any amount of running is better than none.”
While this conclusion might seem obvious to runners, the science has been fairly mixed, says public health researcher Željko Pedišić of Victoria University in Melbourne, Australia. “Some studies found a significant benefit of running, but others did not,” he says.
Also unclear was whether the duration or intensity of running mattered. Researchers who study the effects of running think about the activity in terms of doses, as though it were itself a medicine. Pedišić says that while it might make sense that more running would yield greater health benefits, some studies have sparked debate by suggesting that higher levels of running — more than 250 minutes a week — could actually negate any benefits in terms of mortality.
Pedišić and his colleagues tried to make sense of these conflicting findings by pooling and reanalyzing data from previous studies, an approach known as a meta-analysis. They settled on 14 previously published studies, which collectively asked 232,149 participants about their running habits and then tracked their health over a period of time from 5 ½ to 35 years.
Over the course of each study a total of 25,951 participants died, allowing the researchers to look for statistical associations between running and risk of death.
The researchers found that runners, even those who reported running as infrequently as once a month, had a 27 percent reduced risk of death from any cause compared with non-runners. Each study differed slightly in how they defined a runner, making it difficult to say exactly how little running is necessary for a benefit, though Pedišić says taking just a few strides a week is almost certainly not enough.
Still, the lower risk of early death was more or less the same across all running doses, from running no more than once a week for less than 50 minutes to running every day for a weekly total of 250 minutes. “All these doses of running are significantly associated with lower risk of death,” Pedišić says. “There was no significant difference between frequency, duration or pace,”
“Not finding a trend does not mean that the trend does not exist,” Pedišić cautions. A trend could be too small to be detected within the sample size. Studying the health effects of heavy running can be difficult because there aren’t many people who run that much, he says.
While more evidence is needed to determine if there is an upper limit to how much running is beneficial, this study fits with other research finding health benefits for any level of activity, says Angelique Brellenthin, a kinesiologist at Iowa State University in Ames who was not involved in the study, “Any amount of physical activity that you can fit into your schedule is good for you,” she says.