Community-based Intervention Effects on Older Adults' Physical Activity

To fully examine the effects of these experimental components, The investigators have delineated Primary, Secondary and Exploratory Aims: Primary Aim: Determine which experimental intervention component(s) increase PA among community-dwelling older adults post-intervention: immediately, 6 months, and 12 months. Hypothesis: Participants receiving the interpersonal set of behavior change strategies (conditions 2 and 4) will have clinically meaningful increases in PA post- intervention (at all 3 time-points), compared to participants not receiving these strategies (conditions 1 and 3). Secondary Aim: Determine which experimental intervention component(s)decrease fall occurrence and increase quality of life (QOL) among community-dwelling older adults 12 months post-intervention. Hypotheses: Participants receiving the set of interpersonal behavior change strategies will have clinically meaningful reductions in falls and increases in QOL, 12 months post-intervention, compared to participants not receiving these strategies. Exploratory Aim: Evaluate experimental intervention component effects on targeted psychosocial constructs (social support; readiness; self-regulation) and physical constructs (functional leg strength and balance), which are theorized as mechanisms of change--and whether these mechanisms mediate the effects of experimental intervention components on PA and falls. Hypotheses: Receiving the interpersonal behavioral change strategies, relative to not receiving these strategies, will elicit increases in targeted psychosocial constructs and increases in physical constructs, which in turn will mediate the intervention's effects on PA behavior and falls.