IntroductionSmoking and insufficient physical activity (PA), independently but especially in conjunction, often lead to disease and (premature) death. For this reason, there is need for effective smoking cessation and PA-increasing interventions. Identity-related interventions which aim to influence how people view themselves offer promising prospects, but an overview of the existing evidence is needed first. This is the protocol for a scoping review aiming to aggregate the evidence on identity processes and identity-related interventions in the smoking and physical activity domains.MethodsThe scoping review will be guided by an adaption by Levac et al of the 2005 Arksey and O’Malley methodological framework, the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses: Extension for Scoping Review (PRISMA-ScR) and the 2017 Joanna Briggs Institute guidelines. It will include scientific publications discussing identity (processes) and/or identity-related interventions in the context of smoking (cessation) and/or physical (in)activity, in individuals aged 12 and over. A systematic search will be carried out in multiple databases (eg, PubMed, Web of Science). Records will be independently screened against prepiloted inclusion/exclusion criteria by two reviewers, using the Active Learning for Systematic Reviews machine learning artificial intelligence and Rayyan QCRI, a screening assistant. A prepiloted charting table will be used to extract data from included full-text articles. Findings will be reported according to the PRISMA-ScR guidelines and include study quality assessment.Ethics and disseminationEthical approval is not required for scoping reviews. Findings will aid the development of future identity-related interventions targeting smoking and physical inactivity.

UNSTRUCTURED Background and objective: Smoking and physical inactivity are two key preventable risk factors of cardiovascular disease. Yet, as with most health behaviors, they are difficult to change. In the interdisciplinary Perfect Fit project, scientists from different fields join forces to develop an evidence-based virtual coach that supports smokers in quitting smoking and increasing their physical activity. Intervention content, design and implementation, and lessons learned are presented to support other research groups working on similar projects. Methods: Six different approaches were used and combined to support the development of the Perfect Fit virtual coach. The approaches used are: (1) literature reviews, (2) empirical studies, (3) collaboration with end-users, (4) content and technical development sprints, (5) interdisciplinary collaboration, and (6) iterative proof-of-concept implementation. Results: The Perfect Fit intervention integrates evidence-based behavior change techniques with new techniques focused on identity change, big data science, sensor technology, and personalized real-time coaching. Intervention content of the virtual coaching matches the individual needs of the end users. Lessons learned include ways to optimally implement and tailor interactions with the virtual coach (e.g., clearly explain why the user is asked for input, tailor the timing and the frequency of the intervention components). Concerning the development process, lessons learned include strategies for effective interdisciplinary collaboration and technical development (e.g., finding a good balance between end-users wishes and legal possibilities). Conclusion: The Perfect Fit development process was interactive, iterative, and challenging at times. Our experiences and lessons learned can inspire and benefit others.