Not all cues are equal: A systematic review and three-level meta-analysis of context consistency, physical activity and habit strength.

Although models on habit formation identify the importance of contextual cues as a prerequisite for physical activity (PA) habit formation, no quantitative synthesis has yet established which cue dimensions matter most for habit strength and PA behaviour. This study primarily examined the relationships of context consistency with PA behaviour and PA habit strength, compared effect sizes across five cue dimensions and explored potential moderators. A systematic review and meta-analysis was conducted, including a search of six electronic databases. A three level random effects model was employed to account for effect size dependency. A total of 14 independent studies involving 6069 participants were integrated. Context consistency was significantly correlated with both PA behaviour (r = 0.11) and PA habit strength (r = 0.20). Although effect sizes were small, they are consistent with population-level benchmarks in the PA literature. Only temporal consistency and routine consistency were significantly correlated with PA behaviour; consistency of temporal, social, location, routine and mood cues showed significant positive associations with PA habit strength; no studies examined associations involving object cues. PA operationalisation (frequency vs. duration) moderated the consistency-behaviour relationship, with stronger effects when PA was operationalised as frequency rather than duration. Additionally, PA habit strength was found to be significantly positively correlated with PA behaviour, with a medium-to-large effect size. These findings indicate that cue dimensions differentially relate to PA outcomes, with temporal and routine cues emerging as key targets for behaviour-focused interventions, supporting a shift toward cue-specific PA promotion strategies.