Facilitating an Exercise Habit and Identity Via the Multi-Process Action Control Model- A Randomized-Controlled Trial

The limitations of applying social cognitive models to understand physical activity (PA) have led to the emergence of several new PA models within the past decade. The Multi-Process Action Control (M-PAC) is a comprehensive PA model that proposes intention is established from outcome expectations, perceived capability, and opportunity, then the success of translating this to behavior depends on affective judgments and behavioral-regulation. Over time, M-PAC proposes that behavior is can become maintained through the formation of identity and habit. The purpose of this study was to investigate the trajectory of change of these M-PAC constructs across time in a randomized controlled trial. Participants (n=85) were inactive new gym members and were randomized into a control (n=41) or intervention (n=44) group. The intervention group attended a workshop and received a booster phone call follow-up at week four. Measures for both groups included accelerometry and M-PAC at baseline and eight week follow-up.