Abstract
BACKGROUND/OBJECTIVES: To test the hypothesis that a long-term structured, moderate intensity physical activity (PA) program is more effective than a health education (HE) program in reducing the risk of s elf-reported dependency and disability in basic activities of daily living (BADLs), disability in instrumental ADLs (IADL), and mobility disability. DESIGN: The Lifestyle Interventions and Independence for Elders (LIFE) study was a multicenter, single-blinded randomized trial. SETTING: University-based research clinic. PARTICIPANTS: Thousand six hundred and thirty five sedentary men and women aged 70-89 years, who had functional limitations, defined as a score ≤9 on the Short Physical Performance Battery. INTERVENTION: Participants were randomized to a structured, moderate intensity PA program (n = 818) that included aerobic, resistance, and flexibility exercises or to a HE program (n = 817). MEASUREMENTS: All outcomes were derived by self-report using periodic interviews that asked about the degree of difficulty and receipt of help during the past month. Dependency was defined as "receiving assistance" or "unable" to do ≥1 activities. Disability was defined as having "a lot of difficulty" or "unable" doing ≥1 activities. Severe disability was defined as reporting difficulty or being unable to perform ≥3 activities. RESULTS: Over an average follow-up of 2.6 years, the cumulative incidence of BADL dependency was 15.2% among PA and 15.1% among HE participants (HR = 1.0, 95% CI = 0.78-0.1.3). Intervention groups had similar rates of incident BADL disability, IADL disability and reported mobility disability. Reporting severe mobility disability (HR = 0.78, 95% CI = 0.64-0.96) and ratings of difficulty on mobility tasks were reduced in the PA group. CONCLUSION: A structured physical activity intervention reduces reported severe mobility disability and difficulty on mobility tasks, but not BADL and IADL disability in older adults with functional limitations.