Strength and Gamification in Physical Education: Effects of a gamified pediatric resistance training program on muscular fitness, enjoyment, and motivation in schoolchildren

Most children fail to meet physical activity (PA) guidelines, including muscle-strengthening recommendations, despite the strong association between muscular fitness (MF) and long-term health. This study examined the effects of a school-based pediatric resistance training (PRT) FunctionalHIIT program, delivered with or without gamification, on MF, body composition, PA profile, enjoyment, and motivation. A cluster-randomized controlled trial was conducted with 254 primary schoolchildren (127 boys, 127 girls; 11.10 ± 0.63 years) from six public schools in Valencia, Spain. Over an 8-week intervention integrated into Physical Education (PE) lessons, schools were allocated to one of three groups: PRT FunctionalHIIT with gamification (EG + G), PRT FunctionalHIIT (EG), or a control group (CG). Outcomes were analysed using mixed-design factorial ANOVA (time × group) with Bonferroni-adjusted post hoc tests. Significant time × group interactions were observed across all MF outcomes (all p < 0.001). Both experimental groups improved selected MF components, with EG + G showing significant gains in push-ups, standing long jump, and single-leg hop compared with EG and CG (p < 0.001). Significant interactions were also found for enjoyment, intrinsic motivation, and identified regulation (p < 0.001), with the EG + G reporting higher enjoyment than CG and lower amotivation than EG and CG (p < 0.05). No consistent interaction effects were observed for body composition or overall PA profile, although sedentary behavior was lower in EG + G at post-intervention (p < 0.05). These findings support that PRT FunctionalHIIT implemented during PE is a feasible and engaging school-based approach to enhance MF, enjoyment, and motivation among children, particularly when combined with gamification. TRIAL REGISTRATION: ClinicalTrials.gov (NCT06145529). Registered on 24/11/2023.