Background:

Physical inactivity and sedentary levels among children and adolescents are significant concerns. The school setting presents an ideal scenario for implementing strategies aimed at improving physical activity (PA) levels and reducing sedentary behaviours. However, most of the interventions have primarily focused on children, and limited evidence is available for adolescents. This paper presents the design, measurements, and interventions implemented in the ACTIVE CLASS study, which aim to assess the effects of two interventions on PA levels, sedentary time, health-related physical fitness academic indicators, cognition, and markers of psychological health among secondary education students.

Methods:

: A randomized controlled study is conducted with a total of 292 students from six schools (7 th and 8 th grade) in Spain (three in Cadiz and three in Caceres). One school from each study region is randomly assigned to either the active break intervention group, the physically active learning intervention group, or the control group. The interventions have a duration of 16 weeks. Nine main measurement categories are assessed: PA and sedentary time, health-related physical fitness, academic indicators, cognition, psychological health, motivational variables, dietary patterns, sociodemographic characteristics, and qualitative information. Three temporal moments of evaluation are distinguished: pre-intervention, post-intervention (week 16) and retention measurement (four weeks after the intervention). Qualitative information is assessed solely during the post-intervention measurement.

Discussion:

To the best of our knowledge, the ACTIVE CLASS study is the first of its kind in Spain to evaluate the effects of incorporating active breaks and physically active learning in secondary education. Moreover, this project will offer valuable and innovative training to the educational community, enabling them to implement teaching methodologies that have the potential to enhance academic performance and improve the quality of life for their students. Trial registration: NCT05891054 (clinicaltrials.gov), 06/06/2023.