Physical activity provides substantial health benefits yet physical inactivity is one of the most challenging problems of these days. Development in mHealth and eHealth applications, such as wearable technology, create vast opportunities but are still insufficiently used to promote sustainable physical activity. To enhance the development of such products, participation and cooperation of professionals with different knowledge and expertise is required. We developed a board game called COMMONS to enhance interdisciplinary collaboration in the design of health-related wearable technologies. In this paper we present the design process of COMMONS, results of the play sessions and discuss the future development of COMMONS and the possible implications within the field of Human-Computer Interaction.