Abstract
Low motor competence (MC) and inhibited psychosocial development are associated with mental health difficulties. Improving children's MC through school-based physical activity interventions emphasising psychosocial development may therefore be a mechanism for promoting positive mental health. This study describes and provides reflective insights into the co-creation of 'Move Well Feel Good', a primary school physical activity intervention to improve children's MC and mental health. Class teachers, school leaders, physical activity specialists, and children (aged 8-9 years) participated in a series of co-creation workshops. Stakeholders' knowledge and experiences were integrated with existing research evidence using creative methods (e.g., post-it note tasks, worksheets, and drawings) to facilitate discussion. The co-creation process culminated in stakeholder consensus voting for one of three proposed intervention ideas. Children cited physical and mental health benefits, enjoyment with friends, and high perceived competence as motives for being physically active. Opportunities to develop MC across the different segments of the school day were identified by adult stakeholders, who perceived children's lack of resilience, an overloaded curriculum, and poor parental support for physical activity as barriers to intervention implementation. The chosen intervention idea received six out of a possible twelve votes. Co-creation projects are specific to the contexts in which they are implemented. This study reinforces the complex nature of school-based intervention development and highlights the value of engaging with stakeholders in co-creation processes.