A carefully structured, moderate physical activity program can reduce risk of losing the ability to walk without assistance, perhaps the single most important factor in whether vulnerable older people can maintain their independence, a study has found.
Older people who lose their mobility have higher rates of disease, disability, and death. A substantial body of research has shown the benefits of regular physical activity for a variety of populations and health conditions. But none has identified a specific intervention to prevent mobility disability.
In this large clinical study, researchers found that a regular, balanced, and moderate physical activity program followed for an average of 2.6 years reduced the risk of major mobility disability by 18 percent in an elderly, vulnerable population. Participants receiving the intervention were better able to maintain their ability to walk without assistance for 400 meters, or about a quarter of a mile, the primary measure of the study.
Results of the large clinical trial, conducted by researchers at the University of Florida, Gainesville and Jacksonville, and colleagues at seven other clinics across the country, were published online on May 27, 2014, in the Journal of the American Medical Association. The researchers were supported by the National Institute on Aging (NIA) and the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.
"We are gratified by these findings," said Richard J. Hodes, M.D., director of the NIA, which was the primary sponsor of the trial. "They show that participating in a specific, balanced program of aerobic, resistance, and flexibility training activities can have substantial positive benefits for reducing risk of mobility disability. These are actionable results that can be applied today to make a difference for many frail older people and their families."
The Lifestyle Interventions and Independence for Elders (LIFE) trial included 1,635 sedentary men and women aged 70-89 at risk of disability, who were randomly assigned to a program of structured, moderate-intensity physical activity or to a health education program focused on topics related to successful aging. The diverse participants were recruited from urban, suburban, and rural communities.
Led by Marco Pahor, M.D., of the University of Florida, the study was also conducted at field sites at Northwestern University in Chicago; Pennington Biomedical Research Center in Baton Rouge, Louisiana; Stanford University in Palo Alto, California; Tufts University in Boston; the University of Pittsburgh; Wake Forest University in Winston-Salem, North Carolina; and Yale University in New Haven, Connecticut. Data management and analysis were coordinated by Wake Forest University.
Participation in the study averaged 2.6 years. The physical activity group of 818 people gradually worked up to the goal of 150 minutes of weekly activity, including 30 minutes of brisk walking, 10 minutes of lower extremity strength training, 10 minutes of balance training, and large muscle flexibility exercises. Their programs took place at a clinic twice a week and at home three or four times a week. The 817 people in the comparison group participated in weekly health education workshops for the first 26 weeks, followed by monthly sessions thereafter. They also performed five to 10 minutes of upper body stretching and flexibility exercises in each session. Participants in both groups were assessed every six months at clinic visits.
Adherence to the program was measured by attendance at sessions and by questionnaires in which participants recorded the number of hours per week that they were physically active. In addition, participants' activity was recorded for one week during each year of the trial through an accelerometer, a small belt device that measures physical activity.
"At the beginning of this trial, all the participants were at high risk for mobility disability," said Evan Hadley, M.D., director of the NIA Division of Geriatrics and Clinical Gerontology. "At the start, they were able to walk about a quarter of a mile without a cane, walker, or help of another person. But they did have sedentary lifestyles and low scores on some standard physical tests that measure risk for disability. The study shows it is never too late for exercise to have a positive effect for a significant portion of frail older people."
Principal investigator Pahor noted that participants attended more sessions and stayed in the study longer than anticipated. He also noted that people in the intervention group were very enthusiastic about the exercise program. "When we finished the exercise program at our site, the people were so disappointed that the classes were over," he said. "We know that many of them are continuing to exercise and we are so pleased that they have kept up with this."
In 2011, NIA launched Go4Life (http://go4life.nia.nih.gov/), a national exercise and physical activity campaign, based on previously demonstrated benefits of exercise for healthy community-dwelling adults age 50 and older. The LIFE study adds to that evidence with findings that older people vulnerable to disability can also be included among those who could reap rewards from regular physical activity. Go4Life (http://go4life.nia.nih.gov/) emphasizes endurance, strength, flexibility, and balance exercises.