title: Modeling developmental changes in yo-yo intermittent recovery test level 1 in elite pubertal soccer players.
abstract: OBJECTIVE
  To model the development of soccer-specific aerobic performance, assessed by the Yo-Yo Intermittent Recovery Test Level 1 in 162 elite pubertal soccer players, age 11-14 y at baseline.
  
  
  METHODS
  Longitudinal multilevel modeling analyses comprised predictors related to growth (chronological age, body size [height and weight] and composition [fat mass, fat-free mass]), and motor coordination [3 KÖrperkoordination Test für Kinder subtests: jumping sideways, moving sideways, backward balancing] and estimated biological-maturation groups (earliest [<percentile 33] and latest maturers [>percentile 66]).
  
  
  RESULTS
  The best-fitting model on soccer-specific aerobic performance could be expressed as -3639.76 + 369.86 × age + 21.38 × age² + 9.12 × height - 29.04 × fat mass + 0.06 × backward balance. Maturity groups had a negligible effect on soccer-specific aerobic performance (-45.32 ± 66.28; P > .05).
  
  
  CONCLUSIONS
  The current study showed that the development of aerobic performance in elite youth soccer is related to growth and muscularity and emphasized the importance of motor coordination in the talent-identification and -development process. Note that biological maturation was excluded from the model, which might endorse the homogeneity in estimated biological-maturation status in the current elite pubertal soccer sample.
authors.affiliation: Dept of Movement and Sports Sciences, Ghent University, Ghent, Belgium.
authors.forename: Dieter
authors.initials: D
authors.lastname: Deprez
authors.forename: Joao
authors.initials: J
authors.lastname: Valente-Dos-Santos
authors.forename: Manuel
authors.initials: M
authors.lastname: Coelho E Silva
authors.forename: Matthieu
authors.initials: M
authors.lastname: Lenoir
authors.forename: Renaat M
authors.initials: RM
authors.lastname: Philippaerts
authors.forename: Roel
authors.initials: R
authors.lastname: Vaeyens
mesh_terms: D000293:Adolescent; D000367:Age Factors; D054874:Athletic Performance / Q000502:physiology*; D050218:Body Fat Distribution; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D005080:Exercise Test; D006801:Humans; D008297:Male; D011627:Puberty; D012916:Soccer / Q000502:physiology*