title: The reliability of a rugby league movement-simulation protocol designed to replicate the performance of interchanged players.
abstract: OBJECTIVE
  This study assessed the reliability of a rugby league movement-simulation protocol, relative to interchanged players (RLMSP-i).
  
  
  METHODS
  Fifteen male participants completed 2 trials of the RLMSP-i, separated by 1 wk. The RLMSP-i comprised low- to moderate-intensity running, interspersed by high-intensity sprinting and tackling activity, based on global positioning system (GPS) data recorded during Super League performances.
  
  
  RESULTS
  The lowest coefficient of variation (CV ± 95% CI) was observed for total m/min during both interchange bout 1 (1.1% ± 0.2%) and bout 2 (1.0% ± 0.2%). The percentage of heart rate peak and ratings of perceived exertion demonstrated CVs of 1.2-2.0% and 2.9-3.5%, respectively. The poorest agreement between trials was found for blood lactate concentration (16.2% ± 2.8%). In no case was the CV smaller than the smallest worthwhile change, yet in every case the moderate changes were larger than the CV.
  
  
  CONCLUSIONS
  The RLMSP-i's reliability is sufficient to enable the detection of moderate changes in various performance and physiological measurements that accurately simulate some, but not all, aspects of rugby league matches.
authors.affiliation: School of Science and Technology, University of New England, Armidale, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Waldron
authors.forename: Jamie
authors.initials: J
authors.lastname: Highton
authors.forename: Craig
authors.initials: C
authors.lastname: Twist
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D005538:Football / Q000502:physiology*; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009068:Movement / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult