Background: Two of the most prominent limitations of traditional social cognitive models used to understand moderate-to-vigorous physical activity (MVPA) are the gap between intention and behaviour and the lack of consideration of implicit processes in behavioural enactment. Thus, new models are now being examined that attempt to consider these potential limitations. Multi-Process Action Control (M-PAC) is one such attempt to build a more comprehensive schematic, whereby intention is established via the means of constructs from traditional social cognitive theories (i.e., outcome expectations, perceived capability), but the success of translating this intention to behaviour depends on behavioural-regulation (self-regulatory tactics) (BR), affective judgments (expected pleasure) (AJ) and opportunity (time, access). Over time, M-PAC proposes that habit (stimulus -behaviour bonds) and identity (role-behaviour bonds) develop from performing the behaviour and largely contribute to the maintenance of PA.