The running list of benefits of running (puns!) just got longer: A study from the University of Colorado at Boulder and Humboldt State University in Arcata, Calif., found consistent runners slow down the aging process.

The study, published in PLOS ONE, recruited 30 older adults (15 men and 15 women) who were an average age of 69, and already walking or running as their form of exercise three times a week. After preliminary health screenings, participants were asked to run on a treadmill at various speeds: 1.6 mph, 2.8 mph, and 3.9 mph. Researchers found older runners were as energy efficient as runners in their 20s, as well as better walkers than older participants who stick to walking. Older walkers, researchers surprisingly found, expend the same amount of energy as older, sedentary adults.

"It was surprising to find that older adults who regularly run for exercise are better walkers than older adults who regularly walk for exercise," Owen Beck, a graduate student at CU-Boulder, said in a press release. "The take-home message of the study is that consistently running for exercise seems to slow down the aging process and allows older individuals to move more easily, improving their independence and quality of life," he said.

There's a longstanding, great debate over which is aerobic activity is healthier, walking or running. Running may be the star of this study, but walking isn't necessarily usually (especially if you perfect your form). Daily strolls lead to improve physical health and psychological well-being. The American College of Sports Medicine said physical activity of any kind is in an aging adult's best interest, with "a regular exercise program is an effective way to reduce and/or prevent a number of the functional declines associated with aging."

It's just, according to this study, walking isn't as nergy efficient as running. "Because we found no external biomechanical differences between the older walkers and runners, we suspect the higher efficiency of senior runners is coming from their muscle cells," researchers explained.

Mitochondria are the "powerhouses of the cell." They take in nutrients, break them down, and they create chemical energy. This energy is known as adenosine triphosphrate, and the present study defined it as power for a person's muscle fibers, which helps us move, lift object, and, of course, run. People who regularly work out have more mitochondria, thus more energy and power in their muscles. However, there's still a lot to learn about the role mitochondria plays in older runners.

Until then, good luck on your next run slash living forever. Maybe.

Source: PLOS ONE. 2014.