Effects of school-based interventions on motivation towards physical activity in children and adolescents: A systematic review and meta-analysis

Introduction: Assuming that motivation is the key to initiate and sustain beneficial health behaviors, the aim of this systematic review was to analyze the effects of school-based physical activity interventions on a variety of motivational outcomes towards PA in school-aged children and adolescents. Methods: A comprehensive literature search was carried out in six electronic databases to identify randomized controlled trials and quasi-experimental trials examining the effects of PA interventions implemented during the regular school day, e.g., during physical education lessons or lunch breaks. Primary outcomes of interest were students' motivation, basic psychological needs, goal orientation, enjoyment, and motivational teaching climate in physical education. Meta-analyses were conducted for these outcomes using Comprehensive Meta-analysis software. Secondarily, intervention effects on students' PA behaviors were examined and the findings summarized narratively. Methodological quality of studies was evaluated using the Cochrane Collaboration's tool for assessing risk of bias for randomized trials; certainty of evidence on outcome level was evaluated using the GRADE approach. Results: In total, 57 studies carried out between 2001 and 2018 were included in this review. Sixteen individual meta-analyses were performed and revealed significant pooled effects for the outcomes enjoyment (g = 0.310), perceived autonomy (g = 0.152), identified regulation (g = 0.378), intrinsic motivation (g = 0.419), self-determination index (g = 0.672), task/mastery climate (g = 0.254), ego/performance climate (g = −0.438), autonomy supportive climate (g = 0.262), task goal orientation (g = 1.370), ego goal orientation (g = −0.188). The narrative data synthesis indicated an increase in students' PA behavior. The overall risk of bias was high across all studies and certainty of evidence of meta-analyzed outcomes ranged from very low to moderate. Moderate certainty of evidence was found for ego/performance climate and ego goal orientation. Conclusions: Meta-analyses suggest that school-based PA interventions may be effective in increasing a variety of motivational outcomes. However, the certainty of evidence was limited in the majority of outcomes. Further research is needed to identify effective intervention strategies that increase students’ motivation towards PA.