Running as little as 30 to 60 minutes per week — or perhaps just 5 to 10 minutes per day — could greatly reduce the risk of heart attack and stroke, a new study suggests.
And it's not even important how fast you run, researchers reported Monday in the Journal of the American College of Cardiology.
In fact, researchers found that compared to non-runners, runners of any kind had a 30 percent lower risk of death from all causes and a 45 percent lower risk of death from heart attack or stroke.
"Our study showed that only fairly small doses of running were needed to produce these profound benefits," said study co-author Dr. Carl Lavie, medical director of preventive cardiology at the John Ochsner Heart and Vascular Institute in New Orleans. "Even running less than six miles per week, running less than an hour per week at paces less than 10 minute miles were still producing very substantial reductions in cardiovascular mortality."
While it's long been known that exercise can prolong life, until now it was assumed that benefit came only with at least 75 minutes of vigorous activity per week.
For the new study, researchers followed 55,137 adults aged 18 to 100 at the beginning of the study for an average of 15 years. At the outset none of the study participants reported having a heart attack, a stroke, or cancer. By the end of the study, 3,413 volunteers had died, 1,217 of them from heart attack or stroke. Those who ran even a little bit were less at risk.
The new results are good news to Lauren Rubinstein, a 34-year-old mother of two with a hectic life. Rubinstein runs with some friends who are signed up with a group called "Moms in Training."
"Finding time to exercise is quite challenging," Rubinstein said. "Being busy like myself, it is good to know that even a short amount of time will keep me healthy."
The observational study doesn't prove that low levels of running make your heart healthier, said Dr. Gregg Fonarow, a professor at the David Geffen School of Medicine at the University of California, Los Angeles and co-director of the UCLA Preventive Cardiology Program.
Still, he said, "this and prior research does suggest that there may be important health benefits that can be achieved by sedentary adults becoming active, such as beginning and staying with a low level running program. Even at a low level of running — only 30 minutes a week and less than 6 miles an hour— an associated benefit was observed."
It may only take minimal activity to change the way our bodies behave, said Dr. Vonda Wright, an orthopedic surgeon and medical director for the University of Pittsburgh Medical Center's Lemieux Sports Complex.
"There is a misconception that you have to be a marathon runner to have an effect on health," Wright said. "But that is not true. It may be that a very small daily investment makes a difference — and purposeful choices."
Wright suspects these small amounts of exercise are enough to wake our bodies from hibernation mode.
"On a genetic level we are programed to move," she explained. "Our bodies don't know whether we are hunting and gathering right outside the cave or having to travel long distances to find food. Moving around keeps the genes that transcribe for mobility and muscle and bone health turned on. If our bodies perceive that we are just sitting around, it's as if we are waiting for winter to be over and we go into storage mode."