Reducing Sedentary Behavior vs. Increasing Physical Activity in Older Adults

This study is a randomized trial that will compare the effects of two, 12-week activity interventions on patterns of physical activity, physical health, and quality of life measures in 40 older adults who are able to walk for exercise. One intervention will target 150 minutes per week of home-based moderate exercise (e.g. brisk walking), consistent with current recommendations. The other intervention will target a decrease in time spent in sedentary behaviors (e.g. sitting) of 60 minutes per day. Both interventions will wear an activity armband which will allow them to self-monitor their activity or sedentary behavior in real time using a smartphone. The armband will also provide objective data to an interventionist that will facilitate the intervention. The main outcome will be time spent in moderate exercise.

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.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥60 years
* Currently engage in \<60 minutes of MVPA per week
* Ability to complete a 400 meter walk test without an assistive device
* Access to a computer and compatible smartphone (Andriod or iPhone) for the use of the BodyMedia® Fit System to monitor Moderate -to - Vigorous physical activity or sedentary behavior
* Ability to provide medical clearance to participate in this study from their primary care physician

Exclusion Criteria:

* Unable to provide informed consent
* Household member on study staff
* Current or planned enrollment in another physical activity or weight loss program
* Cardiovascular event (heart attack, stroke, heart failure, revascularization procedure) in the last 6 months
* Current use of beta-blockers or other medication that could affect heart rate
* Currently treated for psychological issues, or taking psychotropic medications within the previous 6 months
* Comorbid condition that would limit participation in exercise (e.g. uncontrolled hypertension, severe arthritis, use of a assistive mobility device, currently undergoing treatment for cancer)
* \>3 alcoholic beverages per day