Physically active learning is a pedagogical approach combining movement with learning in curricular lessons. Increasing evidence suggests the approach benefits education and physical activity outcomes amongst young people. Research in this field has largely focused on primary schools, with little attention given to its potential for adolescents, for whom effective school-based physical activity interventions are lacking. My mixed-methods research seeks to combine health and education paradigms to explore how physically active learning might be implemented successfully in British secondary schools, including initiating the co-design of an intervention with key stakeholders.