Antecedents and mediators of the association between adolescents' intention and physical activity: a cross-sectional study in seven European countries

About 80% of adolescents report insufficient physical activity (PA) worldwide. Beyond the association of attitudes, family and friends' support, and perceived behavioural control (PBC) with intention, self-regulation strategies are expected to underlie the association between intention and action. Particularly, action planning and self-monitoring, as well as the perceived energy needed to develop these strategies, may explain the relationship between intention and PA. However, existing evidence remains scarce and contrasted among adolescents. In a large sample of 13,136 adolescents from seven European countries, we examined the antecedents of intention. We further investigated whether action planning and self-monitoring mediated the association of intention with self-reported PA, as well as whether perceived energy predicted PA through these self-regulation strategies. Structural equation modeling showed that attitudes, PBC, family and friends' support were all associated with intention (b > 0.08, p < .001). Intention (direct effect, b = 0.23, p < .001) and PBC were associated with PA (b = 0.22, p < .001). Action planning (indirect effect, b = 0.06, p < .001) and self-monitoring (indirect effect, b = 0.10, p < .001) partly mediated the relationship of intention with PA. Perceived energy was associated with PA through the partial mediating effect of action planning (indirect effect, b = 0.05, p < .001) and self-monitoring (indirect effect, b = 0.11, p < .001). Our results suggest that both action planning and self-monitoring underlie the association between intention and PA among European adolescents and that perceived energy could be an antecedent of these self-regulation strategies.