This article presents a study aimed at validating the implementation of an active playground system with different movement zones and measuring the effects on pupils. The realisation of an active playground was built through the development of collaborative research, carried out by interactions between researchers, pupils and the teaching team. Six schools in Belgium, located in the Province of Luxembourg, participated in the study. The movements on the playground of 125 pupils aged between 10 and 13 years were measured using a pedometer. The creation of a fidelity index for the implementation of the active schoolyard system made it possible to quantify the importance of the variables essential for the proper implementation of the system. The results showed that the variables that most explain the variance in the number of steps per minute during breaks are gender, the active profile of the pupils, the surface area, the introduction of interventions on the playground and the atmospheric conditions. The question of the sustainability of the effects of the device will be discussed as well as the analysis from an ecological perspective.