title: Fitkids Treadmill Test: Age- and Sex-Related Normative Values in Dutch Children and Adolescents.
abstract: BACKGROUND
  Recent research has shown that the Fitkids Treadmill Test (FTT) is a valid and reproducible exercise test for the assessment of aerobic exercise capacity in children and adolescents who are healthy.
  
  
  OBJECTIVE
  The study objective was to provide sex- and age-related normative values for FTT performance in children and adolescents who were healthy, developing typically, and 6 to 18 years of age.
  
  
  METHODS
  This was a cross-sectional, observational study.
  
  
  METHODS
  Three hundred fifty-six children and adolescents who were healthy (174 boys and 182 girls; mean age=12.9 years, SD=3.7) performed the FTT to their maximal effort to assess time to exhaustion (TTE). The least-mean-square method was used to generate sex- and age-related centile charts (P3, P10, P25, P50, P75, P90, and P97) for TTE on the FTT.
  
  
  RESULTS
  In boys, the reference curve (P50) showed an almost linear increase in TTE with age, from 8.8 minutes at 6 years of age to 16.1 minutes at 18 years of age. In girls, the P50 values for TTE increased from 8.8 minutes at 6 years of age to 12.5 minutes at 18 years of age, with a plateau in TTE starting at approximately 10 years of age.
  
  
  CONCLUSIONS
  Youth who were not white were underrepresented in this study.
  
  
  CONCLUSIONS
  This study describes sex- and age-related normative values for FTT performance in children and adolescents who were healthy, developing typically, and 6 to 18 years of age. These age- and sex-related normative values will increase the usefulness of the FTT in clinical practice.
authors.affiliation: E.M.W. Kotte, MSc, Fitkids Foundation, Box 75751, 1070 AT Amsterdam, the Netherlands. elles@fitkids.nl.
authors.forename: Elles M W
authors.initials: EM
authors.lastname: Kotte
authors.affiliation: J.F. de Groot, PhD, Utrecht University of Applied Sciences, Utrecht, the Netherlands; Child Development and Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands; and Partner of Shared Utrecht Pediatric Exercise Research Lab, Utrecht, the Netherlands.
authors.forename: Janke F
authors.initials: JF
authors.lastname: de Groot
authors.affiliation: B.C. Bongers, PhD, Child Development and Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht; Partner of Shared Utrecht Pediatric Exercise Research Lab; and Department of Epidemiology, School for Public Health and Primary Care, Maastricht University, Maastricht, the Netherlands.
authors.forename: Bart C
authors.initials: BC
authors.lastname: Bongers
authors.affiliation: A.M.F. Winkler, MD, Fitkids Foundation.
authors.forename: Alexander M F
authors.initials: AM
authors.lastname: Winkler
authors.affiliation: T. Takken, PhD, Child Development and Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, and Partner of Shared Utrecht Pediatric Exercise Research Lab.
authors.forename: Tim
authors.initials: T
authors.lastname: Takken
mesh_terms: D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands; D010809:Physical Fitness / Q000502:physiology*; D012016:Reference Values