Prolonged sitting time in adults has become a major societal issue with far-reaching health, economic, and social consequences. The objective of this study is to reduce sedentary behaviour in office workers by integrating physical activity with work. In this case study, we present Workwalk, a concept to encourage and facilitate office workers to have a walking meeting. This idea arose by merging a traditional health research approach with an iterative design process. With this method, it was possible to integrate behaviour change techniques effectively into an interaction design process.