Predicting physical activity behavior among university students using the multi-process action control framework.

Most university students do not engage in enough physical activity (PA) despite the known physical and mental health benefits. Action control theories such as the Multi-Process Action Control (M-PAC) framework have been proposed to better understand the translation of intentions into action by incorporating post-intentional processes. However, the explanatory power of the M-PAC framework beyond traditional social cognitive constructs has received limited attention. This study examined the predictive utility of the M-PAC framework for explaining variance in self-reported and device-measured PA behavior among university students. A total of 2418 undergraduate students (Mean age = 19.1 ± 1.73 [SD] years) completed an online survey that included a self-reported measure of moderate-to-vigorous PA (MVPA) as well as constructs outlined in the M-PAC framework: instrumental and affective attitudes, perceived capability and opportunity, behavioral regulation, habit and identity. A subsample (n = 376) also wore an ActiGraph wGT3x-BT accelerometer on their non-dominant wrist for seven full days to assess MVPA. Robust linear regression models were computed to investigate associations between M-PAC framework constructs and PA behavior. Findings showed the M-PAC framework explained as high as 14.3 % and 37.9 % of the variance in device-measured and self-reported MVPA, respectively. Regulatory (behavioral regulation), and reflexive (habit and identity) processes were significant predictors of self-reported MVPA when examining the full M-PAC framework, whereas the role identity dimension of PA identity was the only significant predictor of device-assessed MVPA. Taken together, these results reinforce the importance of post-intentional processes, specifically role identity, in understanding PA behavior among university students.