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Full list of author information is available at the end of the articleBackground Prevalence of obesity and overweight is increasing among children and adolescents throughout the world [1]. At the same time it has been shown that physical activity (PA) and aerobic fitness have decreased particularly in the less fit pediatric population [2-4]. Taken together, the health consequences of these trends may be a future adult popu-lation with high prevalence of obesity and metabolic ab-normalities [5]. PA has been suggested as an important factor in preven-tion of both obesity and lifestyle diseases [5-7]. Schools pro-vide an advantageous setting for encouraging a healthy lifestyle among children and for enhancing PA [8], since school interventions can reach children from all risk groups [9], while stigmatization of children at risk likely is avoided. Previous school-based intervention studies addressin