To use a randomized controlled trial to test the effectiveness of four goal-setting strategies within a gamification intervention to increase physical activity among adults at elevated risk for ASCVD.

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of mortality in the United States. While increased physical activity can reduce this risk, less than half of adults in the United States meet the minimum recommendation guidelines for physical activity. Gamification, or the application of game design elements to non-game settings, has demonstrated promise in increasing physical activity when designed using insights from behavioral economics. However, the best way to design goal-setting within these interventions has not been well-examined. In this randomized controlled trial, the investigators will evaluate the effectiveness of four different goal-setting strategies within a gamification intervention to increase physical activity among adults with elevated risk for ASCVD. The trial will include a 2-week run-in period to estimate a baseline, followed by an 8-week introductory phase, an 8-week maintenance phase, and then after the intervention is completed an 8-week follow-up period.

Inclusion Criteria:

• Age 18 years or older;
• ability to read and provide informed consent to participate in the study;
• diagnosis of clinical ASCVD or a 10-year ASCVD risk score ≥ 7.5% calculated according to the 2013 ACC/AHA guidelines;
• Smartphone or tablet compatible with application for the wearable activity tracking device.

Exclusion Criteria:

• Conditions that would make participation infeasible such as inability to provide informed consent, illiteracy or inability to speak, read, and write English;
• conditions that would make participation unsafe such as pregnancy or being told by a physician not to exercise;
• already enrolled in another study targeting physical activity;
• any other medical conditions or reasons he or she is unable to participate in a physical activity study for 24 weeks;
• baseline step count of 10,000 steps or greater.

Individual participant data will not be made available