Methods:A total of 350 children (grade 3; 8-9 years of age) from six schools in Granada (Spain) will be enrolled in one of the 8-week interventions (one intervention per school; 50 children per school) or a control group (no intervention school; 50 children). Outcomes will include physical activity (measured by accelerometry), physical fitness (assessed using the ALPHA fitness battery), anthropometry (height, weight and waist circumference), sleep health (measured by accelerometers, a sleep diary, and sleep health questionnaires), academic achievement (grades from the official school's records), and health-related quality of life (child and parental questionnaires).To assess the effectiveness of the different interventions on objectively measured PA and the other outcomes, the generalized linear model will be used.