Running regularly as you age may help you walk more efficiently, which can improve your mobility and quality of life.

Running after middle age might not be the waste of time many believe it is. A new study shows that older adults who run regularly use less energy while walking than those who only walk regularly, an improvement that could help seniors maintain mobility as they age.

“What we found is that older adults who regularly participate in highly aerobic activities — running in particular — have a lower metabolic cost of walking than older, sedentary adults and also lower than seniors who regularly walk for exercise,” said the study’s lead author Justus Ortega, a professor of kinesiology at Humboldt State University, in a press release.

Senior runners consumed 7 to 10 percent less energy while walking than senior walkers. The rate of energy use by older runners was similar to that of young, sedentary adults — not quite the fountain of youth, but still a big improvement, considering that the loss of mobility can have a big impact on quality of life.

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The study, published Nov. 20 in PLOS One, included 30 healthy senior men and women, with an average age of 69. All of them exercised regularly; they had been walking or running for at least 30 minutes three or more times a week for six or more months prior to the start of the study.

To measure walking efficiency, the researchers studied oxygen consumption, carbon dioxide production, and factors like the length of a person’s stride as the volunteers walked on a treadmill at three different speeds.

Senior walkers and runners shared similar walking patterns, but had different levels of walking efficiency, so the researchers suspect that the difference lies inside their muscles.

“Because we found no external biomechanical differences between the older walkers and runners,” said study co-author Rodger Kram, a professor of physiology at the University of Colorado, Boulder, “we suspect the higher efficiency of senior runners is coming from their muscle cells.”

In addition to the overall health boost of regular exercise, running provides strength training for the lower body, which could spill over into improved walking. Other activities, such as walking quickly or uphill, or vigorous cycling, may be equally beneficial.

To really understand the benefits of running later in life, you only need to talk to longtime runners.

“I clearly feel younger than I should at this age,” said Steve Viegas, a 65-year-old runner from Reading, Massachusetts, who is a member of Mystic Runners and the New England 65+ Running Club.

Though Viegas has been running since high school (with some time off after college for an injury), he’s seen seniors successfully start a running routine.

“It’s very exciting for people that enter late in life. It’s transformative, unbelievably transformative,” he said. “Quite often, you can hit your personal record before you start to see the effect of aging.”

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Making the transition, either from younger runner to older runner, or from a sedentary lifestyle to a more active one, requires patience and dedication.

“As we get older, a lot of things change,” said Dr. Thomas Ryan, director of the Heart and Vascular Center at Ohio State University. “You have to pay more attention to those changes as you get older. They become more and more important as we try to exercise without getting injured.”

Paying attention includes keeping an eye out for signs of distress — such as chest pain, shortness of breath, lightheadedness, or fainting — and reporting these to your doctor. If you’re starting a new exercise program from scratch, it’s also a good idea to check in with your doctor beforehand.

Whatever your age, the benefits of exercise — including a stronger heart, more robust bones and muscles, and improved balance — are worth the struggles you may face starting out.

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“The benefits of exercise seem to be maintained throughout adult life and later in life,” said Ryan. “We just have to be a little bit smarter about it and use some of these common sense points to make sure we can do it without hurting ourselves.”

That’s something senior runners can be thankful for this year, and non-runners can ponder while they load up on Thanksgiving leftovers.