School is identified as the main pillar of the fight against sedentariness in youth. Several models of active schools have been described in the literature and, under the umbrella of the school policy enhancing physical activity (PA), five main dimensions can be identified (Physical education, Active transportation, Life environment, Sport at school, PA in the classroom). This underlines that, if the PE teacher is considered as the corner stone of the PA promotion at school, (s)he is not alone to create the conditions aiming to permit to the children to reach the PA level recommended daily. Integrating more PA in the classroom seems to be a promising approach for children lifestyle as well as for their overall learning. Worldwide, initiatives are proposed in order to convince classroom teachers to integrate more often PA in their educational activities. Nowadays, it seems determining to share experiences in order to identify good practices and solutions to the current problems that teachers can encountered on the field. The goal of this presentation is to illustrate two concrete examples of projects implemented in primary schools in Wallonia, Belgium. We will describe the teaching context as well as the main findings provided by a systematic data analysis conducted during these experiments. The first study focused on three classes proposing Brain Breaks (BB) videos during a 10 weeks period. The attitude of the pupils and the teaching staff opinions were analyzed. In the second study, varied PA breaks (BB video, games, and video developed by the pupils) were proposed during periods of two to four weeks. Data from participant observation and questionnaires were used. In both studies, findings support the planning of PA during classroom. Even if more controlled research designs would be necessary in order to determine the evidence of the results, we can state that practitioners and children involved in the projects showed really positive reactions about these opportunities to be more active.