MoST-Influenced Behavioral Intervention for Walking

This study is a randomized, factorial experiment using the basic Science of Behavior Change (SOBC) approach to efficiently test the effects of four distinct behavior change techniques (BCTs), goal setting, action planning, self- monitoring and feedback, hypothesized to engage one key behavioral mechanism of action (MoA-self-efficacy for walking) for improving daily walking by at least 1000 steps per day in persons who have been objectively verified as sedentary and are at risk for cardiovascular disease. Participants who self-report themselves as physically sedentary and possess at least one risk factor for cardiovascular disease are eligible for a 4-week baseline period in which they must demonstrate adherence to Fitbit activity tracking use, completion of survey measures, and be objectively verified as sedentary. Participants who successfully complete baseline will proceed to the 8-week intervention phase of the study. They will be randomized to one of 16 possible intervention arms and receive one or more behavior change techniques shown to be efficacious in promoting greater physical activity. Behavior change techniques will be delivered via text message each morning with the goal of increasing low intensity physical activity by walking 1,000 steps more than the baseline step average. One group (control) will not receive any BCT messages. Upon completion of the intervention phase, participants will continue to have their step counts continuously monitored during the 12-week follow-up phase. All participants will complete bi-weekly surveys throughout the entire duration of the study (baseline, intervention, follow-up).