The final, definitive version of this paper has been published in Journal of Health Psychology, November 2017, doi: https://doi.org/10.1177/1359105317739098, published by SAGE Publishing, All rights reserved.This study examined the constructs of Capability, Opportunity, and Motivation from the COM-B model and their influence on moderate-to-vigorous physical activity (MVPA). Using a prospective survey design, 186 healthy adults completed measures representing the Theoretical Domains Framework mapped to the COM-B, and MVPA one week later. The main indicators for the COM constructs were ‘habits’ (Capability), ‘subjective norms’ (Opportunity), and ‘exercise self-identity’ (Motivation). Motivation (77%) and MVPA (50%) were strongly predicted, with Capability and Motivation as key drivers of behaviour. Motivation was a strong mediator for Capability on behaviour. Future research should consider this approach for other populations and behaviours.Peer reviewe
