title: Sex differences in time to task failure during early pubertal development.
abstract: BACKGROUND
  We compared fatigability and activation of elbow flexor muscles in children at 3 pubertal stages during a sustained submaximal contraction.
  
  
  METHODS
  In 72 healthy children (39 boys) aged 11 ± 3 years (range, 8-14 years), differences in fatigability (time to task failure) and muscle activation were compared at 3 Tanner stages (T1-T3).
  
  
  RESULTS
  Time to task failure and muscle activation were similar between boys and girls at prepubertal Tanner stage 1. Time to task failure was briefer for girls than boys at Tanner stages 2 and 3 and was predicted by the coactivation indices and percent body fat in girls. Muscle torque was the only predictor for the time to task failure in boys.
  
  
  CONCLUSIONS
  Differences in fatigability and muscle coactivation were evident during the initial pubertal stages (T2 and T3), but not before the onset of puberty (T1).
authors.affiliation: Department of Integrative Physiology, University of Colorado, Boulder, Colorado, USA; Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Rudroff
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Holmes
authors.forename: Edward L
authors.initials: EL
authors.lastname: Melanson
authors.forename: Megan M
authors.initials: MM
authors.lastname: Kelsey
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D001823:Body Composition / Q000502:physiology; D002648:Child; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011627:Puberty / Q000502:physiology*; D012737:Sex Factors; D013647:Task Performance and Analysis; D013997:Time Factors
keywords: body composition; children; coactivation; muscle fatigability; physical activity