Structured exercise may enhance seniors' physical functioning

A structured exercise program may boost the physical well-being of sedentary seniors who are at risk of losing independent functioning, a new study to be published in the November 2006 Journal of Gerontology: Medical Sciences has found.

The study also showed that the program holds promise for lowering older people's chances of major walking disability, and that older adults can safely begin a program of moderate exercise.

The findings are reported in a special section of the journal addressing the effects of exercise in older people.

The magnitude of the effects was encouraging to the researchers, who said that the pilot study confirms the feasibility and safety of testing the approach in a larger, more definitive randomized clinical trial involving older adults.

Results of the Lifestyle Interventions and Independence for Elders - or LIFE - pilot study will be presented Nov. 17 at the Gerontological Society of America's annual scientific meeting. The research, supported by the National Institute on Aging (NIA), a component of the National Institutes of Health, was conducted at four field centers nationwide. The University of Florida was the administrative coordinating center.

"As U.S. life expectancy rises, functional decline and disability among older people are growing public health and clinical concerns," says NIA Director Richard J. Hodes, M.D. "This pilot study helps us to understand better the relationship between exercise training and mobility, which is a key to maintaining older adults' independence and quality of life, and provides a basis for designing more definitive large-scale clinical trials."

"Lower-extremity functioning is a very powerful marker for overall function and the risk of disability. This research suggests that a multi-faceted program of aerobic, strength, balance and flexibility exercises can make a difference for older adults by significantly improving their walking ability," adds Jack M. Guralnik, M.D., Ph.D., acting chief of the NIA's Laboratory of Epidemiology, Demography and Biometry.

Participants were invited to join the study if they exercised for fewer than 20 minutes a week; were between 70 and 89 years of age; and had a low physical performance battery score, which is based on three assessments: walking speed, balance and the ability to rise from a chair. At the start of the study, participants had to walk 400 meters - about a quarter of a mile - within 15 minutes without sitting or using an assistive device such as a cane. The participants were followed for an average of 1.2 years.

Half of the 424 study participants were randomly assigned to a year-long physical activity program incorporating individualized counseling and supervised and home-based exercises that included endurance, strengthening, flexibility and balance training. The other half of the participants - the control group - took part in a "successful aging" health education program that discussed nutrition, medications, foot care, preventive services and other health topics, and included instructor-led arm and shoulder flexibility exercises.

At six and 12 months, scientists found that average physical performance scores for the exercise group were significantly better than those of the control group. They also found that by the end of the trial, people in the exercise group were more likely to maintain their 400-meter walking speed.

"This analysis showed that, compared with those who received health education, participants in the physical activity group had a lower risk of becoming unable to walk 400 meters," says the study's principal investigator, Marco Pahor, M.D., of the University of Florida, Gainesville. "This finding is encouraging, although the pilot study was not large enough to reach a definitive conclusion. A larger-scale study could provide invaluable data about the importance of physical activity in older adults."

The four study field centers were the Cooper Institute (Dallas, Texas), Stanford University (Palo Alto, Calif.), the University of Pittsburgh (Pittsburgh, Pa.) and Wake Forest University (Winston-Salem, N.C.). The project also included investigators at Yale University (New Haven, Conn.); Tufts University (Boston, Mass.); the University of California, San Diego; and the University of California, Los Angeles. Wake Forest University served as the Data Management, Analysis and Quality Control Center.