title: Two-year changes in anthropometric and motor ability values as talent identification indexes in youth soccer players.
abstract: OBJECTIVE
  The present study examined 2-year changes in anthropometric variables and motor abilities in elite male youth soccer players to identify potential talent identification indexes.
  
  
  METHODS
  This was a cross-sequential study examining two different age groups at two time points.
  
  
  METHODS
  Height, weight, 40-m sprint speed, muscular power (5-step bounding), and change of direction (COD) ability (10 m×5 COD) were measured in 12- and 14-year-old soccer players and repeated after 2 years (at 14 and 16 years of age). Correlations and changes in ranking between the two measurements were determined.
  
  
  RESULTS
  Both groups had small ranking changes in height (12-14-year-olds: r=0.80, 14-16-year-olds: r=0.89; p<0.01), weight (r=0.94, r=0.80; p<0.01), 40-m sprint speed (r=0.81, r=0.90; p<0.01), and muscular power (r=0.48, r=0.64; p<0.05), with a statistically significant correlation between the initial values and those obtained 2 years later. However, 10m×5 COD ability had a large ranking change, with no statistically significant correlation observed between the first- and second-year values.
  
  
  CONCLUSIONS
  Because of the minimal ranking change in sprint speed in normal circumstances of soccer practice, linear sprint speed has the potential to be a useful talent identification index for youth soccer players. On the other hand, muscular power and COD ability is changeable during growth period suggests that these parameters is not useful for talent identification index.
authors: Faculty of Sport Sciences, Waseda University, Japan. Electronic address: toitsu_hirose@waseda.jp.
authors: Norikazu
authors: N
authors: Hirose
authors: Department of Youth Academy, JEF United Football Club, Japan.
authors: Taigo
authors: T
authors: Seki
mesh_terms: D000293:Adolescent; D001076:Aptitude / Q000502:physiology*; D054874:Athletic Performance / Q000502:physiology*; D001827:Body Height / Q000502:physiology*; D002648:Child; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology*
keywords: Change of direction; Muscular power; Soccer; Speed; Talent identification