title: A systematic review and meta-analysis of interventions designed to increase moderate-to-vigorous physical activity in school physical education lessons.
abstract: OBJECTIVE
  Physical education (PE) that allows students to engage in moderate-to-vigorous physical activity (MVPA) can play an important role in health promotion. Unfortunately, MVPA levels in PE lessons are often very low. In this review, we aimed to determine the effectiveness of interventions designed to increase the proportion of PE lesson time that students spend in MVPA.
  
  
  METHODS
  In March 2012, we searched electronic databases for intervention studies that were conducted in primary or secondary schools and measured the proportion of lesson time students spent in MVPA. We assessed risk of bias, extracted data, and conducted meta-analyses to determine intervention effectiveness.
  
  
  RESULTS
  From an initial pool of 12,124 non-duplicate records, 14 studies met the inclusion criteria. Students in intervention conditions spent 24% more lesson time in MVPA compared with students in usual practice conditions (standardized mean difference=0.62).
  
  
  CONCLUSIONS
  Given the small number of studies, moderate-to-high risk of bias, and the heterogeneity of results, caution is warranted regarding the strength of available evidence. However, this review indicates that interventions can increase the proportion of time students spend in MVPA during PE lessons. As most children and adolescents participate in PE, these interventions could lead to substantial public health benefits.
authors.affiliation: School of Science and Health, University of Western Sydney Locked Bag 1797, Penrith 2751, Australia. c.lonsdale@uws.edu.au
authors.forename: Chris
authors.initials: C
authors.lastname: Lonsdale
authors.forename: Richard R
authors.initials: RR
authors.lastname: Rosenkranz
authors.forename: Louisa R
authors.initials: LR
authors.lastname: Peralta
authors.forename: Andrew
authors.initials: A
authors.lastname: Bennie
authors.forename: Paul
authors.initials: P
authors.lastname: Fahey
authors.forename: David R
authors.initials: DR
authors.lastname: Lubans
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D015444:Exercise / Q000502:physiology*; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D010806:Physical Education and Training; D012572:School Health Services