School physical education-based reinforced program through moderate-to-vigorous physical activity improves and maintains schoolchildren's cardiorespiratory fitness: A cluster-randomized controlled trial

Summary Objective The main aim was to examine the effects of a physical education-based reinforced program through outdoor physical activities and body expression on cardiorespiratory fitness in secondary students. A secondary aim was to analyze the physical activity levels during the physical education-based development and reinforced programs. Methods A sample of 92 secondary students (Mage 12.4 ± 0.7 years), from five classes, were cluster-randomly assigned into 3 groups: an experimental group without a reinforced program of physical activities [non-reinforced group (NRG)], an experimental group with a reinforced program [reinforced group (RG)], and a control group (CG). The NRG and RG students performed a physical fitness development program twice a week for nine weeks. Then, the RG completed a reinforced program through outdoor physical activities and body expression twice a week for six weeks. Students’ cardiorespiratory fitness was measured at the beginning and at the end of the development program, as well as at the end of the reinforced program. Physical activity levels were measured objectively through a heart rate monitor and subjectively by a self-reported scale during physical education sessions. Results The results of the mixed two-way [3 × 3; group (NRG, RG, CG) × time (pre-intervention, post-intervention and post-maintenance)] analysis of covariance [performance (s): F = 11.926, P Conclusion A reinforced program of nine weeks (initial development) and six weeks (maintenance thorough other physical education contents) allowed teachers to increase and maintain students’ cardiorespiratory fitness levels and to develop other curricular contents at the same time.