title: Effects of school-based squat training in adolescent girls.
abstract: BACKGROUND
  For adolescent girls, less information on the effects of school-based exercise training is available from earlier studies. This study aimed to determine the effects of school-based squat training on body composition and muscular strength in adolescent girls.
  
  
  METHODS
  Fifty-two girls (13.8±0.6 years) were randomly assigned to the training and control groups. The training group conducted an 8-week body mass-based squat exercise training (100 reps/day, 45 sessions) as a part of after-school activity. Body composition (bioelectrical impedance analyzer), muscle thickness at the thigh anterior (ultrasound), and maximal isometric knee extension strength (myometer) were determined before and after the intervention. The magnitude of maturation was assessed using Tanner stage criteria of pubic hair before the intervention.
  
  
  RESULTS
  After the intervention, percent body fat decreased in the training group, but increased in the control group. The relative changes in lean body mass, muscle thickness and muscular strength were similar between both groups. In the training group, the relative change in knee extension strength was correlated to the magnitude of maturation before the intervention.
  
  
  CONCLUSIONS
  For adolescent girls, an 8-week body mass-based squat training is feasible for lowering percent body fat. In addition, the strength improvement for the knee extensors partially depends on the magnitude of maturation at start of the intervention.
authors.affiliation: National Institute of Fitness and Sports in Kanoya, Kanoya, Kagoshima, Japan - y-takai@nifs-k.ac.jp.
authors.forename: Takaya
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takai
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fukunaga
authors.forename: Eiji
authors.initials: E
authors.lastname: Fujita
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanehisa
mesh_terms: D000293:Adolescent; D001823:Body Composition / Q000502:physiology*; D005260:Female; D006801:Humans; D007564:Japan; D007717:Knee; D007719:Knee Joint; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D055070:Resistance Training / Q000379:methods; D013848:Thigh