The 'scientific' approach for the physical activity behaviour change

A 'theoretical' approach to behaviour changeUnderpinning behaviour change interventions with a theoretical base significantly improves the effectiveness of such interventions in comparison to those that do not utilise theory to inform intervention design (Taylor, Conner, & Lawton, 2012). As such, interventions should be developed using theoretical insights from behavioural psychology. Atheoretical interventions tend to focus on the techniques to be utilised whereas theoretical approaches initially target the processes involved in change and then identify suitable techniques to achieve the change (Gourlan et al., 2015). When processes are highlighted using non-theoretical designs, an intuitive or 'logical' approach is taken to identify potential targets (i.e., the group lack sufficient efficacy beliefs to engage in exercise). Although appropriate determinants should be identified prior to intervention development, the selection and application of theory to achieve this feat is challenging for those within health psychology. In addition to theory selection, there are several other considerations that must be accounted for to develop and undertake a sound scientific intervention. Taking into account the number of limitations encountered within each consideration, the striving for a science of behaviour change is rather difficult. The purpose of this article is to provide a summary of the scientific approach to changing health behaviours, such as physical activity (PA) and exercise. The paper will first highlight the various stages involved in the development and evaluation of a behaviour change intervention. Problems addressed within these stages will then be discussed. It is hoped that this commentary will provide an insight into how to develop and deliver effective theory-based interventions to promote health enhancing behaviours.Intervention developmentDespite the longevity of behaviour change theories, an explicit call for theoretically informed interventions was only made relatively recently. The Medical Research Council provide robust guidelines on the development of interventions (Craig et al., 2008). Such stages include; theory, modelling, exploratory, randomised control trial, and long term implementation. For example, the designer should first select, amongst many, an appropriate theoretical base for the intervention. Once selected, the relevant determinants should be identified as well as the strategies to target such determinants. Although vigorous, these guidelines do not identify how to navigate through the initial stages (Michie, Johnston, Francis, Hardeman, & Eccles, 2008). For example, it is not clear how a suitable theory should be selected nor how change strategies should be identified. This leaves the question; how should the theory be applied? In addition to these guidelines, Intervention Mapping (Bartholomew, Parcel, Kok, Gottlieb, & Fernandez 2011) and the 'RE-AIM' framework (Reach, Efficacy/Adoption, Implementation, Maintenance model) (Glasgow, Klesges, Dzewaltowski, Bull, & Estabrooks, 2004) have also been developed to facilitate intervention planning. One again, however, the process that intervention designers should undertake lack specificity. Nevertheless, the appeal for a theoretical approach to intervention design offers a starting point for intervention development.The psychological processes of changeThe selection of an appropriate behaviour change theory is important for promoting change. Psychological behaviour change theories attempt to identify the determinants and beliefs associated to behaviour and to therefore target within interventions. For example, the Theory of Planned Behaviour (TPB; Ajzen, 1985) states attitude, subjective norms and perceived behavioural control formulate a behavioural intention and, if under volitional control, this intention will lead to subsequent behaviour. An individual may perceive PA to have many benefits, perceive friends to want them to engage in the behaviour and also have the confidence to undertake the activity. …