title: Annual improvement in fitness test performance for elite junior Australian football cohorts.
abstract: OBJECTIVE
  The study examined the change in fitness test performance of elite junior Australian football cohorts tested over the span of seven years.
  
  
  METHODS
  Annual cross-sectional observation study.
  
  
  METHODS
  A total of 1714 elite junior male Australian football players were eligible for the study and completed annual late pre-season fitness testing between 2009 and 2015. The testing comprised anthropometric (height, mass, and skinfolds) and performance tests (standing vertical jump, left and right foot running vertical jumps, 5- and 20-m sprinting, agility, and shuttle run test). A linear regression analysed the performance change for each test over time for two analyses: (1) the entire cohort, and (2) a stratified analysis of 'high' (top 20% of players) and 'low' (bottom 20% of players) performers for each performance test.
  
  
  RESULTS
  There was a moderate (f(2)=0.20) improvement in the standing vertical jump for the entire cohort. Small (f(2)≥0.03) changes occurred for the right and left foot running vertical jumps, agility, and shuttle run, whilst trivial/small (f(2)≤0.02) changes were observed for skinfolds, 5- and 20-m sprinting for the entire cohort. The most notable difference in the stratified analysis was that the 'low' performance groups had a greater improvement in the shuttle run, and 5- and 20-m sprinting.
  
  
  CONCLUSIONS
  Findings indicate a small overall annual improvement in fitness test performance of elite junior cohorts over time that seems to permeate through both 'high' and 'low' performers for most tests. The results might suggest an increase in the professionalism of players and junior developmental pathways.
authors.affiliation: Sport and Exercise Science, School of Science and Health, Western Sydney University, Australia; Alliance for Research in Exercise, Nutrition, and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Australia. Electronic address: samuel.chalmers@westernsydney.edu.au.
authors.forename: Samuel
authors.initials: S
authors.lastname: Chalmers
authors.affiliation: Alliance for Research in Exercise, Nutrition, and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Australia.
authors.forename: Mary
authors.initials: M
authors.lastname: Magarey
mesh_terms: D054874:Athletic Performance / Q000639:trends*; D001315:Australia; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods*; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D010809:Physical Fitness / Q000502:physiology*; D012420:Running; D013997:Time Factors
keywords: Acceleration; Physical; Physical endurance; Power; Sports; Youth