This PhD is concerned not only with what was produced, such as the validated measurement tool, the findings, and the physical activity intervention, but importantly with how these outputs were developed. Meaningful behaviour change work depends on clear, systematic processes, not simply the end products. This research therefore places strong emphasis on how decisions were made, how evidence was generated and applied, and the rationale that guided the progression from initial insight to intervention design and implementation.         

Key elements of the research were the use of behavioural theory, empirical data, stakeholder insight and the Behaviour Change Wheel to guide the design and refinement of the intervention. Rather than relying on assumptions or isolated findings, the research drew together quantitative data, qualitative insights, and practitioner expertise to support creating a robust behavioural diagnosis that could directly inform the intervention. Collaboration was also central to the process. Engagement with stakeholders, practitioners, and the target population ensured that each phase, from the identification of barriers to the selection of Behaviour Change Techniques and the final design of the programme, could be grounded in real-world context.    

By focusing on these processes, the overarching commentary highlights that the value of the research lies as much in how the intervention was designed as in the intervention itself. The accompanying guide (Portfolio Ouput 4) further illustrates this by making the methods transparent and replicable, showing exactly how theory, evidence, and collaborative decision-making shaped the intervention. Together, they present a clear model for developing behaviour change physical activity interventions that can be both rigorous and practical. 

The development of Thrive, the physical activity intervention presented in this practice-based PhD by Portfolio, emerged from an institutional funding opportunity that ran alongside, but separate from, this PhD. In late 2023, Canterbury Christ Church University’s Sport and Active Health department secured an 18-month grant through the BUCS Active Wellbeing Fund, which supports universities to design place-based physical activity initiatives for staff and students. This funding was obtained independently of the PhD and was not used to support the doctoral research.                                                             

Once the grant was awarded, a natural opportunity for collaboration arose. At the same time, this PhD was generating detailed insights into the physical activity needs of staff and students to then apply the COM-B and Behaviour Change Wheel frameworks to shape a theory-led intervention. The funded project therefore provided a practical context in which these emerging insights and methods could be applied, allowing the research to be conducted in a real-world context. This alignment brought together the department, university stakeholders, and the PhD researcher to co-create a programme that could be both evidence-informed and grounded in the real-world constraints highlighted through the funding brief. The result was Thrive, a collaboratively developed intervention shaped by institutional priorities, behavioural data, and a structured, theory-driven design process.

 

I am a practitioner–researcher with a background in psychology, behaviour change and applied physical activity research. I hold a BSc in Psychology (Sport & Exercise) and an MSc in Sport and Exercise Psychology, providing a strong theoretical and methodological foundation for this PhD. 

Prior to this research, I worked in applied practitioner roles designing, delivering and evaluating physical activity interventions aligned with policy and practice, including Sport England–funded programmes. As an Active Health Coordinator, I applied research insight and statistical analysis to demonstrate impact, led multi-disciplinary teams and volunteers, and produced reports and case studies for funders and stakeholders.  The quality and impact of this work was recognised through the BUCS Physical Activity Excellence Award in both 2018 and 2022.  

My subsequent research roles involved leading and evaluating community-led, inclusive physical activity programmes using mixed-methods approaches, and working closely with local and national stakeholders to embed research into practice.  I have also worked as a sessional lecturer, delivering teaching on psychology of physical activity and health behaviour change, supporting students to bridge theory and practice.

This PhD is shaped by my dual identity as a practitioner and researcher, bringing applied insight, expertise in behaviour change frameworks (including COM-B and the Behaviour Change Wheel), and a commitment to producing evidence that directly supports inclusive, real-world physical activity interventions.



Author note: The candidate was enrolled on the PhD under the name Laura Ackerley and now publishes under the married name Laura Cambar.