A new study by researchers at Humboldt State University is shedding light on an unexpected benefit of bicycling as an exercise in older adults.
The paper, Bicycling Exercise Helps Maintain a Youthful Metabolic Cost of Walking in Older Adults, will be published in the Journal of Aging and Physical Activity. It was co-authored by Daniel Aslan (‘15, Kinesiology, ‘16, MS, Kinesiology) and HSU Kinesiology Professor Justus Ortega, who got significant press a few years ago for a similar study about the effects of running on the aging process.
The study looked at adults over the age of 65—some of whom walk for exercise and some who bicycle for exercise. The researchers discovered that those who ride a bicycle for at least 30 minutes, three times a week were less likely to experience age-related physical decline in walking efficiency than those who simply walked for the same period of time. The study also found that the older cyclists were 9-17 percent more efficient at walking than those who didn’t ride a bicycle.
“What we found is that older adults who regularly participate in high aerobic activities—bicycling in particular—have what we call a lower metabolic cost of walking than older adults who walk for exercise,” says Ortega, who is also director of HSU’s Biomechanics Lab. “In fact, their metabolic cost of walking is similar to young adults in their 20s.”
Metabolic cost is the amount of energy needed to move and it naturally increases as we age. High metabolic cost contributes to making walking more difficult and tiring. Decline in walking ability is a key predictor of morbidity in older adults.
In the study, researchers looked at self-reported older bicyclists over the age of 65—those who rode at least 30 minutes a day, three times a week—and self-reported walkers, those who walked three times a week for 30 minutes. Participants were asked to walk on a treadmill at four speeds (1.7, 2.8, 3.6, and3.9 miles per hour) as researchers measured their oxygen consumption and carbon dioxide production.
Researchers aren’t yet sure what makes cyclists more efficient than walkers but they believe it may have something to do with the mitochondria found in cells. Evidence suggests that people who exercise vigorously have healthier mitochondria in their muscles.
“The bottom line is that cycling keeps you younger, at least in terms of efficiency,” says Aslan, now a Doctoral student at the University of Illinois Champaign.
Future studies are planned to examine whether other highly aerobic activities—such as swimming—may also mitigate age-related physical decline.