Physical activity depends on the individual and is also heavily influenced by their family, social, and geographic environment. For adolescents in particular, the appeal of the activity and motivation are key factors. The study "Intervention auprès des collégiens centrée sur l'activité physique et la sédentarité" (Icaps), the only one of its kind in France, demonstrates that it is possible to increase the level of physical activity among adolescents through initiatives implemented in middle schools.