PRIMARY OBJECTIVE:~I. Determine whether the dyadic behavioral intervention produces greater engagement of moderate-intensity objective physical activity (PA) compared with the individual behavioral intervention.~SECONDARY OBJECTIVES:~I. Determine the effects of the dyadic behavioral intervention on hypothesized intervention mechanisms (e.g., autonomous motivation, social support, autonomy support, self-efficacy), and the associations of those mechanisms with PA outcomes.~II. Determine the effects of the dyadic behavioral intervention on secondary outcomes (i.e., self-reported moderate-intensity PA, lower body strength, blood pressure, anthropometric measures, mean daily steps, sedentary time) compared with the individual behavioral intervention.~III. Determine whether the dyadic behavioral intervention produces greater engagement of moderate-intensity PA compared with the individual control.~OUTLINE: Participants are randomized to 1 of 2 groups.~GROUP 1 (DYADIC INTERVENTION): Participants receive phone calls over 30-45 minutes each from a health coach weekly during month 1, twice monthly during months 2-4, and monthly during months 5-6 for a total of 12 phone calls that focus on identifying needs, practicing autonomy supportive behaviors, and the development of a mutual support plan. Participants also engage in at least one physical activity per week with their partner and monitor their own and each other's activity using a FitBit. Participants also wear an accelerometer for a minimum of 10 hours a day for 7 days. Participants also receive an electronic newsletter twice monthly during months 1-3 and monthly during months 4-6 that provides educational physical activity-related information and tips for overcoming barriers to physical activity.~GROUP 2 (INDIVIDUAL CONDITION): Participants are assigned to one of 2 groups.~GROUP 2A (INDIVIDUAL INTERVENTION): Participants receive phone calls from a health coach as in Intervention I that focus on providing support for behavioral skills, including monitoring physical activity, goal-setting, and problem-solving to overcome barriers to physical activity. Participants utilize a FitBit to monitor their physical activity and receive electronic newsletters twice monthly during months 1-3 and monthly during months 4-6 that provides educational physical activity-related information and tips for overcoming barriers to physical activity. Participants also wear an accelerometer for a minimum of 10 hours a day for 7 days.~GROUP 2B (HEALTH EDUCATION CONTROL): Participants utilize a FitBit to monitor their physical activity and receive electronic newsletters twice monthly during months 1-3 and monthly during months 4-6 to share basic health education related to physical activity and provide support for engagement. Participants also wear an accelerometer for a minimum of 10 hours a day for 7 days.~At completion of study, patients are followed up at 6 and 12 months.
This clinical trial tests the effect of a physical activity intervention that emphasizes support between partners in women who are not physically active. Decisions about and participation in physical activity often involve others in one's social circle, including family and friends. Social support for physical activity and having someone with whom to engage in physical activity may promote behavioral change and help increase moderate-intensity physical activity in inactive women.