Background: Physical activity (PA) is a key component in health promotion and prevention of overweight. Interventions delivered in after-school programs (ASP) have the potential to become a means of ensuring PA among young schoolchildren. This requires a motivational climate, allowing for self-determination and the intrinsic values of the activity, on the activity's character of play. ASP staff could be trained in stimulating all children in physical activities in their everyday life. Physiotherapists in primary care possess knowledge of motor development and learning, and are important contributors to an ASP-based physical activity intervention.