Application of the Multi-Process Action Control Model to Predict Physical Activity During Late Adolescence.

The aim of this study was to apply the Multi-Process Action Control model to examine how the additions of regulatory and reflexive processes predict physical activity (PA) behaviors among adolescents. Our sample included 1,176 Grade 11 students (Mage = 15.85 ± 0.38) recruited from a large school board in Southern Ontario. Participants completed a questionnaire including measures of self-reported PA and PA cognitions derived from the Multi-Process Action Control model. Results found the reflective process explaining 16.5% of the variance in PA, with the additions of regulatory and reflexive processes significantly improving the explained variance by 5.1% and 8.2%, respectively. Final models revealed coping planning (estimate = 45.10, p = .047), identity (estimate = 55.82, p < .001), and habit (estimate = 64.07, p < .001) as significant predictors of PA. Findings reinforce the need for integrative models to better understand PA, with coping planning, habit formation, and development of an active identity to be salient targets for intervention during adolescence.