Abstract
PURPOSE: Physical activity promotion has mostly focused on theories of intention-formation, with the assumption that positive intentions will lead to behaviour. Though necessary, exercise intentions alone are often not sufficient to improve physical activity behaviour. The Multi-Process Action Control (M-PAC) framework builds on previous intention-based theories by including both determinants of intention formation and its translation into behaviour. The purpose of this study was to describe the process of developing a self-guided web-based intervention to promote physical activity among adults using the M-PAC model. PROCEDURES: The development process consisted of the following three phases: 1) Intervention planning: determine intervention needs and requirements; 2) Intervention development: use an iterative process to design a web-based physical activity intervention based on the M-PAC framework; 3) Pilot testing: conduct usability and acceptability assessment on the web-based intervention to further enhance user experience. PRINCIPAL RESULTS: The intervention planning phase suggested that there is a need for web-based physical activity interventions and there is currently no web-based intervention designed using the M-PAC model. In phase two, we adopted an iterative process to develop a 10-week self-guided web-based intervention to help adults (>18 years of age) to meet 150 min of moderate to vigorous physical activity per week. The pilot testing phase yielded valuable feedback on usability, content, and design of the web-based intervention. MAJOR CONCLUSIONS: The development of a web-based physical activity intervention using the M-PAC model could further enhance the effectiveness of web-based interventions and have a significant impact on extending the reach of existing physical activity promotion programs. This study has reinforced the importance of an iterative development process that involves a multi-disciplinary team to design a web-based intervention to promote physical activity. The process enabled the team to clarify the needs for an intervention for our target users, and provided valuable feedback on the design and content of the web-based intervention. Future studies are now needed to evaluate the effectiveness of our web-based intervention.