title: Maturity-related variation in moderate-to-vigorous physical activity among 9-14 year olds.
abstract: BACKGROUND
  This study compared physical activity levels among early, average, and late maturing boys and girls.
  
  
  METHODS
  Physical activity was assessed with an Actigraph accelerometer in 161 (76 boys, 85 girls) 9 to 14 year olds over 7 consecutive days. Anthropometric variables were measured and the maturity offset (ie, years from peak height velocity) was predicted. Biological maturity groups (early, average, and late) were created based on the mean estimated age at peak height velocity for boys and girls separately.
  
  
  RESULTS
  Levels of moderate-to-vigorous physical activity (MVPA) were similar between early, average, and late maturing boys and girls after adjusting for differences in chronological age. Levels of MVPA progressively declined across chronological age in boys and girls (P < .001) and gender differences existed at 10-, 12-, and 13-years, with boys having higher levels than girls (P < .05). When aligned according to biological age, gender-related differences in MVPA did not exist.
  
  
  CONCLUSIONS
  Within this sample of 9 to 14 year old boys and girls, there were no significant differences in MVPA among early, average, and late maturing individuals.
authors: Dept of Exercise and Sport Science, University of Tulsa, Tulsa, OK, USA.
authors: Eric E
authors: EE
authors: Wickel
authors: Joey C
authors: JC
authors: Eisenmann
authors: Gregory J
authors: GJ
authors: Welk
mesh_terms: D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology*; D000367:Age Factors; D015992:Body Mass Index; D001837:Body Weights and Measures; D002648:Child; D002657:Child Development; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D013997:Time Factors