title: Exercise and insulin resistance in youth: a meta-analysis.
abstract: OBJECTIVE
  The prevalence of obesity and diabetes is increasing among children, adolescents, and adults. Although estimates of the efficacy of exercise training on fasting insulin and insulin resistance have been provided, for adults similar estimates have not been provided for youth. This systematic review and meta-analysis provides a quantitative estimate of the effectiveness of exercise training on fasting insulin and insulin resistance in children and adolescents.
  
  
  METHODS
  Potential sources were limited to peer-reviewed articles published before June 25, 2013, and gathered from the PubMed, SPORTDiscus, Physical Education Index, and Web of Science online databases. Analysis was limited to randomized controlled trials by using combinations of the terms adolescent, child, pediatric, youth, exercise training, physical activity, diabetes, insulin, randomized trial, and randomized controlled trial. The authors assessed 546 sources, of which 4.4% (24 studies) were eligible for inclusion. Thirty-two effects were used to estimate the effect of exercise training on fasting insulin, with 15 effects measuring the effect on insulin resistance. Estimated effects were independently calculated by multiple authors, and conflicts were resolved before calculating the overall effect.
  
  
  RESULTS
  Based on the cumulative results from these studies, a small to moderate effect was found for exercise training on fasting insulin and improving insulin resistance in youth (Hedges' d effect size = 0.48 [95% confidence interval: 0.22-0.74], P < .001 and 0.31 [95% confidence interval: 0.06-0.56], P < .05, respectively).
  
  
  CONCLUSIONS
  These results support the use of exercise training in the prevention and treatment of type 2 diabetes.
authors.affiliation: Department of Kinesiology, 330 River Rd, Ramsey Center, University of Georgia, Athens, GA 30602-6554. fedew1mv@uga.edu.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Fedewa
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Gist
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Evans
authors.forename: Rod K
authors.initials: RK
authors.lastname: Dishman
mesh_terms: D000293:Adolescent; D001499:Bayes Theorem; D015415:Biomarkers / Q000097:blood; D002648:Child; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000517:prevention & control*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D016013:Likelihood Functions; D016014:Linear Models
chemical_list: D015415:Biomarkers; D007328:Insulin
keywords: adolescent; child; exercise training; insulin; insulin resistance