Running for Better Walking

Running for exercise may help seniors walk as efficiently as people in their 20s

(RxWiki News) Sometimes you've got to run before you can walk. A new study found that running for exercise may help older people keep some pep in their step.

Seniors who regularly ran for exercise — rather than jogging or walking — expended less energy when they walked and walked as efficiently as 20-year-olds, a new study found.

Walking efficiently can help seniors move more easily and improve their quality of life, said the study authors. Seniors who are efficient walkers may also have more independence.

These researchers said they think small bodies in the cells called mitochondria may be responsible for the increased walking efficiency. They recommended further research to confirm their theory.

"The bottom line is that running keeps you younger, at least in terms of energy efficiency," said study author Rodger Kram, PhD, of the Department of Integrative Physiology at the University of Colorado Boulder, in a press release.

Jim Crowell, head coach at Optimum Performance Training in Scottsdale, Arizona, told dailyRx News that even though it's important for everybody to stay active, he doesn't believe that running is mandatory for everyone. "Some people run extremely poorly, and that can cause a lot of stress and inflammation in the joints," said Crowell, who was not involved in this study.

"I do love for everybody to walk if they have the ability because it is just a primal movement (as is running). We are designed to walk, so I like for people to do that, and especially for older individuals, it really can strengthen their legs and help them get healthier. I have absolutely seen older individuals who can keep up with younger individuals in the walking arena. Those older individuals are often very active on a daily basis," Crowell said.

The researchers, led by Humboldt State University Professor Justus D. Ortega, PhD, studied 30 adults — half male and half female, with an average age of 69 — who either walked or ran regularly for exercise.

All the patients had been following an exercise regime for at least six months. They walked or ran at least three times a week for at least 30 minutes per workout.

To study these patients' walking abilities, Dr. Ortega and team measured how much oxygen the patients used when they walked on a treadmill. The participants walked at speeds of 1.67, 2.8 and 3.91 mph.

When these study authors tested patients at faster speeds, they found that energy demands increased more in walkers than runners.

The researchers measured gross metabolic power consumption — the amount of energy each subject used during the test.

For runners who walked at 3.91 mph, gross metabolic power consumption increased by 86 percent. For walkers who walked at 3.91 mph, gross metabolic power increased by 95 percent. In other words, people who walked for exercise had to work harder than runners to walk at the same speed.

Seniors who ran were better walkers than seniors who walked regularly. The runners were 7 to 10 percent more efficient at walking on a treadmill than walkers.

The older runners’ walking efficiency was similar to that of a young adult who neither walked nor ran for exercise. However, older walkers’ walking efficiency was similar to that of older sedentary adults and 26 percent less efficient than that of younger sedentary adults.

The research team felt that mitochondria — tiny bodies in the muscle cells that produce the chemical energy to power the muscles and make them move — may provide the answer.

As people age, their mitochondria don’t work as well, and they must expend more energy to make movements like walking or running. People who exercise regularly have been found to have more mitochondria in their cells, Dr. Ortega and colleagues noted.

"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," Dr. Ortega said. "It's been known for a long time that as people age their maximum aerobic capacity, or 'horsepower,' declines, and that is true for runners as well. What's new here is we found that old runners maintain their fuel economy."

The study was published online Nov. 20 in PLOS ONE.

The National Institutes of Health funded the study. The authors disclosed no conflicts of interest.

Review Date: 
November 20, 2014