by Marla Paul
CHICAGO — A 20-minute walk around the neighborhood each day could help older adults maintain their ability to walk, according to a national study that included a Northwestern Medicine research site.
Moderate physical activity helped aging adults maintain their ability to walk at a rate 18 percent higher than older adults who did not exercise.
Called the Lifestyle Interventions and Independence for Elders study (LIFE), the study took place across eight field centers.
“The study demonstrates that a moderate intensity exercise program prevents mobility loss in older, sedentary men and women,” said Mary McDermott, M.D., principal investigator of the Northwestern Medicine study site and the Jeremiah Stamler Professor of Medicine at Northwestern University Feinberg School of Medicine. McDermott also is a physician at Northwestern Memorial Hospital.
“This finding has major public health implications because of the large and growing number of older, sedentary men and women in the U.S.,” McDermott added. “Based on our results from the LIFE Study, clinicians should recommend moderate intensity exercise, focused on walking exercise, to prevent mobility loss in older, sedentary men and women.”
The study is particularly important because it includes a population that is typically understudied, the authors said.
The results were published in May in the Journal of the American Medical Association.
Researchers showed that prescribed daily physical activity prevents older adults’ loss of mobility, defined in the study as the ability to walk 400 meters, or about a quarter of a mile. That’s an important distance for older adults, researchers said, equal to a trip from a parked car to a grocery store.
Moderate physical activity not only helped older adults maintain mobility, but also helped prevent the occurrence of long-term mobility loss. The researchers found a 28 percent reduction in people permanently losing the ability to walk easily.
In addition to Northwestern, the centers were at the University of Florida, Jacksonville Brooks Rehabilitation, Pennington Biomedical Research Center, University of Pittsburgh, Stanford University, Tufts University, Wake Forest School of Medicine and Yale University.
The researchers recruited 1,635 sedentary men and women aged 70 to 89. The participants could walk a quarter mile within 15 minutes but were at risk for losing that ability. Low physical performance can be a predictor of early death and higher hospitalization and institutionalization rates, and patients with low physical performance are not often recruited to large studies.
The participants were randomly assigned to two groups. The first walked 150 minutes per week and did strength, flexibility and balance training. They were kept on track with their exercise by two visits to field centers per week. The second group attended health education classes and performed stretching exercises. This phase of the study occurred between February 2010 and December 2013.
Staff members assessed study participants every six months, checking their ability to walk, their body weight, blood pressure and pulse rate, among other measurements. The staff was not told which participants were assigned to physical activity or to the education classes.
A National Institutes of Health and National Institute on Aging Cooperative Agreement funded the study. The National Heart, Lung and Blood Institute provided additional support.
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