Physical activity key to maintaining independence say University of Pittsburgh researchers
Findings from the first long-term study on physical activity and functional ability published in today’s Archives of Internal Medicine
PITTSBURGH, Nov. 24 – Physical activity plays a significant role in maintaining functional ability later in life, according to a study completed by University of Pittsburgh researchers. The study, which is the first long-term prospective study to prove the link between physical activity and function, appears in today's edition of Archives of Internal Medicine.
The study followed 171 post-menopausal women who, from 1982 to 1985, were enrolled in a study to determine the effects of a regular walking routine on health. In 1985, 1995 and 1999 their physical activity levels were assessed through self-reporting and performance-based measures. Researchers found that women who were physically active on a regular basis during this 14-year time span had a noticeably higher level of functional status than women who were inconsistently active or were inactive. This association was maintained even after adjusting for health status.
"Functional status relates directly to what people can do for themselves, so having a high functional status means the person is more likely to be able to live independently," said Jennifer S. Brach, Ph.D., assistant professor of physical therapy, University of Pittsburgh School of Health and Rehabilitation Sciences. "Regular physical activity, which can be as simple as walking, not only helps people to live longer and healthier, it helps them to live with fewer limitations and a better quality of life. With people living longer, this emphasizes that everyone, young and old alike, should be physically active."
Activity levels were measured at all three intervals through a physical activity questionnaire that measured physical activity through sports/leisure activities and number of blocks walked. In 1985, physical activity was objectively measured using a Large Scale Integrated Monitor; in 1999, it was measured using a pedometer.
In 1999, functional status was measured through self-report and performance-based measures. Participants completed a Functional Status Questionnaire which inquired about the amount of difficulty participants had in performing activities of daily living including eating, dressing, doing housework, walking several blocks and climbing stairs. Functional status was objectively measured using a seven-item Physical Performance Test (PPT) in which participants were asked to write a sentence, simulate eating, lift a book to a shelf, put on a jacket, pick up a penny, turn 360 degrees and walk. Gait speed was analyzed using an instrumented walkway.
Findings were consistent for all three tests – gait speed, PPT and self-reported activities of daily living function – over 14 years, physical activity was directly related to improved functional status. Those who were never active were more likely to have difficulties with activities of daily living, had lower PPT scores and lower mean gait speeds than those who were always active. The results for those who were inconsistently active fell between the scores of those who were never active and those who were always active.
"It's important to note that not only is this the first study to show the positive long-term effects of physical activity, it is the first to study performance-based outcomes, not just self-reported outcomes," said Andrea Kriska, Ph.D., associate professor of epidemiology at the University of Pittsburgh Graduate School of Public Health and principal investigator of the study. "We have good results that were received from good measurement techniques; this allows us to say, with little doubt, that physical activity will help people maintain their independence as they age."
The study was funded by the National Institute on Aging, National Institutes of Health, the Foundation for Physical Therapy and the geriatric section of the American Physical Therapy Association.