title: Variable and changing trajectories in youth athlete development: further verification in advocating a long-term inclusive tracking approach.
abstract: Athlete development through adolescence can vary greatly because of maturational processes. For example, variation can be observed in anthropometric and fitness measures with later maturing individuals "catching up" their earlier maturing peers at later time points. This study examined a methodological issue concerning how best to assess anthropometric and fitness change (i.e., "across age categories" or "per year") relative to an age and skill-matched population (N = 1,172). Furthermore, it examined changes in anthropometric and fitness characteristics in 3 cases of youth rugby league players (aged 13-15) across a 2-year period. Findings identified the "per year" method as generating less deviated z-scores across anthropometric and fitness measures (e.g., mean change p < 0.001), suggesting less substantial change in case players relative to the population. When applied to additional players, z-score and radar graphs showed developmental variability and longitudinal change. The possibility of a "later maturing player" increasing anthropometric (e.g., height: player 4 = 3.3 cm; player 5 = 13.2 cm; and player 6 = 15.7 cm) and fitness (e.g., 30-m sprint: player 4 = -0.18 s, player 5 = -0.46 s, and player 6 = -0.59 s) characteristics compared with early maturing players was confirmed. Findings affirm the potential for variable and changing trajectories in adolescent athletes. Practical implications advocate a long-term inclusive tracking approach of athletes, the avoidance of (de)selection, and the reduction of a performance emphasis in adolescent stages of sport systems.
authors.affiliation: 1School of Exercise & Sport Science, Faculty of Health Sciences, The University of Sydney, Sydney, Australia; 2Research Institute of Sport, Physical Activity, & Leisure, Leeds Metropolitan University, Leeds, United Kingdom; and 3Rugby Football League, Red Hall, Leeds, United Kingdom.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Cobley
authors.forename: Kevin
authors.initials: K
authors.lastname: Till
authors.forename: John
authors.initials: J
authors.lastname: OʼHara
authors.forename: Carlton
authors.initials: C
authors.lastname: Cooke
authors.forename: Chris
authors.initials: C
authors.lastname: Chapman
mesh_terms: D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology*; D000367:Age Factors; D054874:Athletic Performance / Q000502:physiology*; D049628:Body Size; D005080:Exercise Test; D005538:Football / Q000502:physiology; D006801:Humans; D010809:Physical Fitness; D012420:Running / Q000502:physiology; D013997:Time Factors