title: Influence of physical contact on neuromuscular fatigue and markers of muscle damage following small-sided games.
abstract: OBJECTIVE
  Physical contact is frequent in rugby league competition and is thought to be a major contributor to the fatigue and creatine kinase (CK) response, although direct evidence is lacking. The aim of this study was to investigate the influence that physical contact had on the fatigue and CK response to small-sided games.
  
  
  METHODS
  Cross-over, counter-balanced study.
  
  
  METHODS
  Twenty-three junior elite rugby league players were divided into two groups. Group one played a contact game on day 1 before playing a non-contact game 72 h later; group two played the games in reverse order. The rules were identical for each game, with the only difference being a 10s contact bout every 50s during the contact game. Upper and lower body neuromuscular fatigue and blood concentrations of CK were assessed immediately before, immediately after, and 12 and 24h after the games. During each game, players wore global positioning system units to provide information on movements.
  
  
  RESULTS
  CK increased after both games, peaking immediately following the non-contact game; CK was still rising 24h following the contact game. The difference between the two conditions was practically meaningful at this point (likelihood=likely, 82%; ES=0.86). There were moderate to large reductions in upper body power following the contact game (ES=-0.74 to -1.86), and no reductions following the non-contact game.
  
  
  CONCLUSIONS
  This study indicates that large increases in blood CK and upper body fatigue result from physical contact. Training sessions involving physical contact should be performed well in advance of scheduled games.
authors: School of Exercise Science, Australian Catholic University, Australia. Electronic address: richard.johnston@acu.edu.au.
authors: Rich D
authors: RD
authors: Johnston
authors: School of Exercise Science, Australian Catholic University, Australia; School of Human Movement Studies, University of Queensland, Australia.
authors: Tim J
authors: TJ
authors: Gabbett
authors: Melbourne Storm Rugby League Football Club, Australia.
authors: Anthony J
authors: AJ
authors: Seibold
authors: School of Human Movement Studies, University of Queensland, Australia.
authors: David G
authors: DG
authors: Jenkins
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D003163:Competitive Behavior / Q000502:physiology; D003402:Creatine Kinase; D018592:Cross-Over Studies; D005538:Football / Q000502:physiology*; D006801:Humans; D009068:Movement / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000473:pathology*; D010809:Physical Fitness / Q000502:physiology
chemical_list: D003402:Creatine Kinase
keywords: Contact sports; GPS; Neuromuscular; Tackling; Training games; Wrestling