title: International normative 20 m shuttle run values from 1 142 026 children and youth representing 50 countries.
abstract: OBJECTIVE
  To develop sex-specific and age-specific international norms for the 20 m shuttle run test (20mSRT) in children and youth (aged 9-17 years), and to estimate the prevalence meeting the FITNESSGRAM criterion-referenced standards for healthy cardiorespiratory endurance (CRE).
  
  
  METHODS
  A systematic review was undertaken to identify papers explicitly reporting descriptive 20mSRT (with 1 min stages) data on children and youth since 1981. Data were included on apparently healthy (free from known disease/injury) 9-17 years old. Following standardisation to a common metric and for protocol differences, pseudo data were generated using Monte Carlo simulation, with population-weighted sex-specific and age-specific normative centiles generated using the Lambda Mu and Sigma (LMS) method. Sex-related and age-related differences were expressed as per cent and standardised differences in means. The prevalence with healthy CRE was estimated using the sex-specific and age-specific FITNESSGRAM criterion-referenced standards for [Formula: see text].
  
  
  RESULTS
  Norms were displayed as tabulated centiles and as smoothed centile curves for the 20mSRT using 4 common metrics (speed at the last completed stage, completed stages/minutes, laps and relative [Formula: see text]). The final data set included 1 142 026 children and youth from 50 countries, extracted from 177 studies. Boys consistently outperformed girls at each age group (mean difference±95% CI: 0.86±0.28 km/h or 0.79±0.20 standardised units), with the magnitude of age-related increase larger for boys than for girls. A higher proportion of boys (mean±95% CI: 67±14%) had healthy CRE than girls (mean±95% CI: 54±17%), with the prevalence of healthy CRE decreasing systematically with age.
  
  
  CONCLUSIONS
  This study provides the most comprehensive and up-to-date set of international sex-specific and age-specific 20mSRT norms for children and youth, which have utility for health and fitness screening, profiling, monitoring and surveillance.
authors.affiliation: Department of Kinesiology and Public Health Education, University of North Dakota, Grand Forks, North Dakota, USA.|Alliance for Research in Exercise, Nutrition and Activity (ARENA), School of Health Sciences & Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Grant R
authors.initials: GR
authors.lastname: Tomkinson
authors.affiliation: Healthy Active Living and Obesity (HALO) Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Lang
authors.affiliation: Healthy Active Living and Obesity (HALO) Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Tremblay
authors.affiliation: School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Dale
authors.affiliation: ParticiPACTION, Toronto, Ontario, Canada.
authors.forename: Allana G
authors.initials: AG
authors.lastname: LeBlanc
authors.affiliation: Healthy Active Living and Obesity (HALO) Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Belanger
authors.affiliation: University of Granada, Granada, Spain.|Karolinska Institute, Huddinge, Sweden.
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega
authors.affiliation: Département de kinésiologie, Université de Montréal, Montréal, Quebec, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Léger
mesh_terms: D000293:Adolescent; D002648:Child; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D010809:Physical Fitness; D012016:Reference Values; D012420:Running
keywords: Adolescent; Children; Endurance