This intervention has been developed by the Spanish Ministry of Health, Social Services and Equality and the Ministry of Education, Culture and Sport to increase the amount of children's PA during PE lessons in primary schools. At the time of this study, any school in Spain could choose to adopt this programme. This intervention includes two sets of eight active PE lessons specifically developed for third grade of primary school. These lessons will replace the original PE lessons in schools assigned to Active PE lesson intervention and integrated intervention. Additionally, this intervention provides some methodological advices to increase the PA time during the PE lesson (i.e. different ways to take attendance or deciding on the most suitable activity given the availability of resources).