Predicting walking and cycling behaviour change using an extended Theory of Planned Behaviour

Introduction: The psychological predictors of behaviour change may differ from the predictors of engaging in behaviour, and there is limited evidence on the associations between psychological constructs and changes in physical activity behaviours such as walking and cycling. This study of observational cohort data examined whether an extended version of the Theory of Planned Behaviour (eTPB) predicted change in walking and cycling for transport and recreation using a population-based sample of adults from three UK municipalities. Methods: We used baseline, 1-year and 2-year follow-up data from the iConnect study. Nine psychological constructs from the eTPB as well as weekly time spent (i) walking and (ii) cycling, each (i) for transport and (ii) for recreation, were self-reported at all time points. Multinomial logistic regression was used to examine associations between baseline eTPB constructs and (i) increases and (ii) decreases in the four behavioural outcomes, adjusted for socio-demographic characteristics. Results: 1796 and 1465 participants provided 1- and 2-year follow-up data, respectively. All eTPB constructs except subjective norms were associated with changes in at least one of the four outcomes, but these amounted to relatively few significant associations among the large number tested. In general, eTPB constructs were more often associated with increases than with decreases in time spent walking and cycling. Conclusions: This is one of the first known studies to examine psychological predictors of change in walking and cycling for transport and recreation using an extended TPB. Future interventions to promote walking and cycling through individually delivered approaches might consider fostering the development of positive attitudes, perceived behavioural control, intentions, and habits for these behaviours.