The purpose of this study is to gather preliminary data that will determine the feasibility of conducting a Phase III, randomized, controlled trial (RCT) that will provide definite evidence in the use of physical exercise to prevent mobility disability in older persons.

As the life expectancy of older Americans increases, prevention of age-associated physical function decline and disabilities has emerged as a major clinical and public health priority. A critical factor in an older person's ability to function independently is mobility, the ability to move without assistance. Older people who lose mobility are less likely to remain in the community, have higher rates of morbidity, mortality, and hospitalizations and experience a poorer quality of life. While several studies suggest that physical activity may prevent physical disability, including mobility disability in both healthy and frail older adults, definitive evidence is lacking. A Phase 3, randomized, controlled trial is needed to fill this evidence gap. Currently data to estimate sample size needs for such a trial are insufficient and further feasibility data should be gathered before such a trial can be effectively designed and implemented.

To refine key trial design benchmarks (including sample size calculations to demonstrate the feasibility of a full-scale trial and refining/developing recruitment, procedures, materials and organizational infrastructure), the LIFE (Lifestyle Interventions for Independence in Elders) study conducts a pilot, single-blind, randomized, controlled trial involving comparison of a physical activity program of moderate intensity to a successful aging program. Approximately 400 sedentary persons aged 70 to <90 years who are at risk of disability are followed for at least one year at four intervention sites: Wake Forest University School of Medicine in Winston Salem, NC; the University of Pittsburgh in Pittsburgh, PA; the Cooper Institute in Dallas, TX; and the Stanford University in Palo Alto, CA. The Administrative Coordinating Center and the Data Management and Quality Control Center are at Wake Forest University School of Medicine.

The LIFE study assesses the combined outcome of major mobility disability, defined as the incapacity to walk 400 meters (m), or death, which will be the primary outcome of the full-scale study. This outcome has not been used in previous randomized, controlled trials, and therefore, a pilot study is needed to assess its incidence rate. Secondary outcomes include ADL disability, major fall injuries and cardiovascular events. LIFE explores the effects of the intervention on physical performance measures, cognitive function, health-related quality of life, and use of health care services. In addition, LIFE explores and performs cost-effectiveness analyses of the intervention.

This pilot study will yield the necessary preliminary data to design a definitive Phase 3, randomized, controlled trial. By providing a conclusive answer regarding whether physical activity is effective for preventing major mobility disability or death, the results of the full-scale trial will have relevant clinical and public health implications, and will fill an important gap in knowledge for practicing evidence-based geriatric medicine.

Inclusion Criteria:

• Men and women ages 70 to 89
• Residency in the area for at least 9 months in the next year
• Summary score of under 10 on the Established Populations for Epidemiologic Studies of the Elderly (EPESE) physical performance battery; ability to complete the 400 m walk test within 15 minutes without sitting and without the use of an assistive device (including a cane) or the help of another person
• Able to understand and perform the required study procedures; no diagnosis of dementia
• Sedentary lifestyle, i.e., has spent less than 20 minutes per week in the past month getting regular physical activity
• Willing to give informed consent, willing to be randomized to either intervention, and to follow the protocol for the group to which they have been assigned
• Successful completion of the behavioral run-in

Exclusion Criteria:

• Potential difficulty adhering to either intervention
• Unable or unwilling to give informed consent or accept randomization
• Participation may be unsafe
• Serious health conditions that would interfere with the intervention goals
• Already physically active to a degree that the adoption of an activity program would be of little additional benefit
• Self-reported inability to walk two blocks
• Use of walker or assistive device to complete the 400 m walk