Antecedents of children's physical activity intentions and behaviour: Predictive validity and longitudinal effects

This study examined the predictive validity and time-lagged relationships in a model of children's physical activity intentions, attitudes, perceived behavioural control (PBC), behaviour and past behaviour using the Theory of Planned Behaviour (TPB; Ajzen, 1985) as a framework. In Study I, 386 children aged 12-14 years completed measures of intentions, attitudes, subjective norm, PBC and past behaviour. Their physical activity behaviour was assessed one week later. Structural equation analyses supported the construct and predictive validity of the TPB with the exception of subjective norms which did not predict intentions. In Study 2, 70 children completed measures of their physical activity attitudes, intentions, PBC and past behaviour. Attitudes, intentions, PBC and recent behaviour were re-assessed five weeks later. The cognitions demonstrated a moderate degree of stability over time and there were some cross-lagged effects between attitudes and PBC. Past behaviour demonstrated additive rather than attenuating effects. These results support the use of the TPB cognitions and past behaviour as a framework to examine children's physical activity behaviour.