Physical activity and the theory of planned behaviour: a scoping review, 2001-2015

Abstract

Background. The theory of planned behaviour (TPB) has proven useful to predict physical activity (PA), but recent research points to the relevance of additional PA predictors such as planning, yet these developments have not been systematically reviewed. Thus, the aim of this scoping review was to provide an overview of trends in this field. A special focus was whether researchers have objectively measured PA and conducted longitudinal designs. Methods. Inclusion criteria were that at least one TPB construct and PA (the latter as either self-report or objective) were assessed without active interventions. We searched several databases (e.g. PubMed, PsycINFO) for studies between 2001 and 2015. Overall, 3884 abstracts were screened, of those 486 were reviewed in full text, and 243 studies qualified for the final sample. Results. In 37 studies (15.2%), planning was assessed. Objective PA measures were used in 17 studies (7.0%) and in 136 studies (56%) at least two measurement time points (MTP) were assessed. Of these 136 studies, only 10 (4.1%) included intensive longitudinal designs (with at least 5 MTP). Eligible studies appeared with greater regularity more recently (r =.70). Most studies were conducted in the USA (55%) or the EU (33%). Discussion. Surprisingly, measures of planning were relatively rare, although scholars have increasingly studied PA with longitudinal designs, as more than half of the studies used two or more MTP. In contrast, there have been very few studies with an intensive longitudinal design or assessing PA with objective measures.