The intention-behaviour gap in physical activity: a systematic review and meta-analysis of the action control framework

OBJECTIVE: Intention is the proximal antecedent of physical activity in many popular psychological models. Despite the utility of these models, the discrepancy between intention and actual behaviour, known as the intention-behaviour gap, is a central topic of current basic and applied research. The purpose of this meta-analysis was to quantify intention-behaviour profiles and the intention-behaviour gap. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Literature search was conducted in June 2022 and updated in February 2023 in five databases. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Eligible studies included a measure of physical activity, an assessment of physical activity intention and the employment of the intention-behaviour relationship into profile quadrants. Only papers published in the English language and in peer-reviewed journals were considered. Screening was assisted by the artificial intelligence tool ASReview. RESULTS: Twenty-five independent samples were selected from 22 articles including a total of N=29 600. Random-effects meta-analysis revealed that 26.0% of all participants were non-intenders not exceeding their intentions, 4.2% were non-intenders who exceeded their intentions, 33.0% were unsuccessful intenders and 38.7% were successful intenders. Based on the proportion of unsuccessful intenders to all intenders, the overall intention-behaviour gap was 47.6%. CONCLUSION: The findings underscore that intention is a necessary, yet insufficient antecedent of physical activity for many. Successful translation of a positive intention into behaviour is nearly at chance. Incorporating mechanisms to overcome the intention-behaviour gap are recommended for clinical practice.