title: Reliability of the 30-15 Intermittent Fitness Test in Semiprofessional Soccer Players.
abstract: OBJECTIVE
  The purpose of this investigation was to determine the reliability of the 30-15 Intermittent Fitness Test (30-15(IFT)) in semiprofessional soccer players.
  
  
  METHODS
  Fourteen male semiprofessional soccer players performed the 30-1(IFT) on 2 occasions separated by 7 d. Reliability was assessed by intraclass correlation coefficient (ICC), typical error of measurement expressed as a coefficient of variation (CV), and smallest worthwhile change (SWC) to determine any significant difference between testing sessions.
  
  
  RESULTS
  Maximal intermittent running velocity (V(IFT)) demonstrated good reliability (ICC = .80) for between-sessions reliability. The CV was 2.5% for between-sessions reliability of the 30-15(IFT). As the SWC (0.70 km/h) falls within the range in which the individual's true score is likely to lie (1.0 km/h), the usefulness of the VIFT was rated as marginal. Despite the usefulness of the 30-15(IFT) being deemed marginal, a change in performance as small as 1.0 km/h (2 stages) in V(IFT) could be considered substantial or real.
  
  
  CONCLUSIONS
  This study demonstrates that V(IFT) in the 30-15(IFT) is reliable, resulting in a reliable assessment of team-sport-specific cardiorespiratory fitness, with changes as small as 1.0 km/h (2 stages) in V(IFT) considered meaningful.
authors.affiliation: Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Thomas
authors.forename: Thomas
authors.initials: T
authors.lastname: Dos'Santos
authors.forename: Paul A
authors.initials: PA
authors.lastname: Jones
authors.forename: Paul
authors.initials: P
authors.lastname: Comfort
mesh_terms: D000328:Adult; D056352:Athletes; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D008297:Male; D010809:Physical Fitness; D015203:Reproducibility of Results; D012420:Running; D012916:Soccer; D055815:Young Adult