Effects of school-based interventions on motivation towards physical activity in children and adolescents: Protocol for a systematic review

Background: Recent studies have observed low levels of physical activity in children and adolescents worldwide. Physical activity interventions are increasingly carried out to counteract this development. The school environment is an ideal setting for such interventions to take place as large numbers of children and adolescents can be addressed. With the assumption that motivation is the key to initiate and sustain beneficial health behaviors, theory-based intervention studies apply motivational strategies to increase students' participation in physical activity. The main objective of this systematic review will be to analyze the effects of school-based physical activity interventions on a variety of motivational outcomes towards physical activity in school-aged children and adolescents. Methods: Comprehensive literature searches will be conducted in multiple electronic databases, including MEDLINE, Scopus, PsycINFO, ERIC, PSYNDEX, Physical Education Index, and SPORTDiscus. We will include randomized controlled trials (RCTs) and quasi-experimental studies examining the effects of school-based physical activity interventions (e.g., physical activity components during school lessons including physical education, or during morning, lunch and afternoon breaks). Primarily extracurricular physical activity interventions will not be considered. The primary outcomes will be students' motivation, basic psychological needs, goal orientation, enjoyment, and motivational teaching climate in physical education. Secondary outcomes will be the students' physical activity behaviors in-class, during school, and in leisure time. Only peer-reviewed articles published in English will be considered. Three reviewers will independently screen all citations and full-text articles, and two reviewers will abstract data. The quality of the included studies will be assessed with the Cochrane Collaboration's tool for assessing risk of bias for RCTs and the GRADE methodology will be used to assess the certainty of the body of retreived evidence. Discussion: In order to increase and maintain physical activity levels in children and adolescents, motivation towards physical activity should be sustained. It is anticipated that the results of this systematic review will provide information as to which strategies implemented in the school setting are effective in increasing students' motivation towards physical activity, and hence increase their physical activity during school and after-school hours. Systematic review registration: PROSPERO CRD42018110306