The goal of this Roybal Center is to both generate intervention development research for promoting physical activity in older adults and launch several independent programs of research. Its first pilot project aims to efficiently identify the distinct, effective behavior change techniques (i.e., building blocks) that are preferred for improving low-intensity physical activity (e.g., walking) in older, otherwise healthy, community-dwelling adults to be included in later-stage multi-behavior change technique interventions. The second pilot project aims to formally test the habit-formation theory to improve walking in a second sample of older, otherwise healthy, community-dwelling adults by employing its behavior change techniques and hypothesized mechanism of action—cognitive automaticity. The projects’ success is contingent on the creation of a practical, science-based, prevention-driven suite of behavioral interventions that are successfully implemented in the real world to improve the health and vitality of older adults.