With exercise, elders can improve weakened physical abilities

With a prescription of regular structured exercise, sedentary elderly are able to safely improve their physical function and may reduce the likelihood they will experience difficulty walking a quarter mile, according to findings from a multicenter pilot study led by the University of Florida Institute on Aging.

UF researchers announced the results of the Lifestyle Interventions and Independence For Elders pilot study, or LIFE, today (Nov. 17) at the Gerontological Society of America's annual meeting in Dallas. The study also appears in the November issue of the Journal of Gerontology: Medical Sciences accompanied by an editorial.

The findings confirm the feasibility of a full-scale clinical trial using physical activity in older people, said Marco Pahor, director of the UF Institute on Aging and the study's principal investigator.

"This pilot demonstrates that the physical activity was extremely safe for the study participants - elderly people at a high risk of becoming disabled," Pahor said.

The pilot study was the first to gather evidence that physical activity can improve the score on a standardized test of lower extremity physical mobility called the Short Physical Performance Battery, or SPPB, the researchers said.

Previous research has found that the score on this performance test is highly predictive of future health problems. People with lower scores on the SPPB assessment are more likely than others to die earlier, have health problems, be institutionalized and become less able to get around.

"I think the result is promising for a full-scale study," said Pahor, a professor and chairman of the department of aging and geriatric research in UF's College of Medicine. "(Previously) we had no definitive empirical evidence that the score on the SPPB test could be modified. We were able to show this is possible, and it is promising that, once tested in a full-scale clinical trial, this intervention may also be shown to modify other health outcomes, such as mobility disability."

Even a small improvement of a half point on the test score's scale of 0 to 12 may translate as a major improvement in an elder person's ability to perform activities of daily living, such as walking across a room, dressing, eating or bathing. A low score, between 0 and 4, is a strong risk factor for disability and death. The LIFE study looked at people with intermediate scores from 4 to 9 to see if exercise could improve or prevent a decline in their scores.

Researchers recruited 424 sedentary elderly participants aged 70 to 89 from the community. Participants first took the SPPB test to establish a baseline score and then were divided into two groups. One group was given a structured physical activity consisting primarily of walking at a moderate intensity for at least 150 minutes a week, coupled with leg stretches, balance exercises and leg-strengthening exercises. The second group was given "successful aging" instruction on good living practices, including information on nutrition, medications, foot care and preventive services. Participants were re-tested twice over an average of 1.2 years.

During the testing period, participants in the physical activity group increased their score from a baseline average of about 7.5 to about 8.5. Participants in the physical activity group also improved their performance on a second assessment, the 400-meter walking test, and had a lower incidence of a major mobility disability, defined as an inability to walk a quarter mile, than did those in the "successful aging" intervention group.

"This analysis showed that, compared with those who received health education, participants in the physical activity group had a 29 percent lower risk of being unable to walk 400 meters," Pahor said.

The LIFE study was conducted at four centers - the Cooper Institute, Stanford University, the University of Pittsburgh and Wake Forest University - and was funded by the National Institute on Aging. The coordinating center was based at UF and the data management, analysis and quality control center was based at Wake Forest University. Investigators from Tufts University, Yale University, the University of California San Diego, UCLA and the NIA also contributed to the study.

"Lower-extremity functioning is a good reflection of overall functioning and disability in older adults. We are encouraged by these results, which demonstrate that a well-designed program combining aerobic, strength, balance and flexibility exercises can make a difference for those who are at high risk of losing mobility function," said Jack M. Guralnik, M.D., Ph.D., co-principal investigator for the study and chief of the NIA's Laboratory of Epidemiology, Demography and Biometry.

The LIFE study researchers are planning to conduct a full-scale study, testing 2,500 adults at 10 sites over four years - the longest study to date to assess whether structured exercise can delay the inability to walk 400 meters, a quarter mile.