Reducing Sedentary Behavior vs. Increasing Physical Activity in Older Adults

Specific Aims: This application proposes to randomize community-dwelling, older adults to one of two, 12-week activity interventions that target either increased moderate-to-vigorous physical activity (MVPA) or decreased sedentary behavior (SED). The primary aim of this research is to evaluate the effect of a behavioral intervention targeting decreased SED vs. increased MVPA on objectively monitored activity (minutes of SED and MVPA). The secondary aim is to evaluate the effect of the SED intervention vs. the MVPA intervention on functional and psychosocial outcomes. To the investigators knowledge, this research will provide unique experimental evidence that SED can be altered in an older adult population and will yield key pilot data on the expected effect size for an intervention targeting SED vs. MVPA.

Background: The older adult population is the least active age group in the U.S. by two distinct metrics: a lack of MVPA and a high rate of SED (sitting without any significant exertion). This represents a public health opportunity because engaging in 150 minutes of MVPA is known to improve the risk of morbidity, mortality, and physical function. SED has emerged as a risk factor for adverse outcomes, independent of MVPA, and observational studies indicate that more SED is linked to an increased risk of clinical outcomes (mortality, diabetes, and cardiovascular disease) and worse aging outcomes, e.g. physical function. However, there exists no experimental data comparing interventions to reduce SED vs. increase MVPA in older adults.

Summary of Methods: The investigators propose a 2-arm randomized trial that will target increasing MVPA (Get Active) vs. decreasing SED (Sit Less) among community-dwelling, older adults from the Pepper Center Mobility Registry. The intervention will consist of a combination of in-person (Weeks 1-4, 6, 8, 10) and phone-based (Weeks 5, 7, 9, 11) individual counseling and will utilize the BodyMedia® Fit System (wearable armband with technology interface) to provide real-time feedback on daily MVPA or SED, which can be used by the subjects to self-monitor and by the interventionist to improve adherence. Assessments at baseline and 12 weeks will include objectively monitored minutes of MVPA and SED by a blinded armband, physical function (short physical performance battery, 400 meter walk, grip strength, gait speed), and assessment of subjective MVPA, SED, physical function, and psychosocial outcomes by questionnaires.