title: Profiling the time-course changes in neuromuscular function and muscle damage over two consecutive tournament stages in elite rugby sevens players.
abstract: OBJECTIVE
  Many International Rugby Board (IRB) sevens competitions require that two tournament stages are played over consecutive weekends, but the impact this has on player physical performance and recovery is lacking. We examined the influence of two consecutive tournaments on neuromuscular function (NMF) and muscle damage in rugby sevens players.
  
  
  METHODS
  Ten elite international rugby sevens players completed this observational study over 2 tournaments, separated by 5 days, during the IRB sevens series.
  
  
  METHODS
  On the morning of day 1 and 2, of both tournament 1 (T1) and 2 (T2), players performed countermovement jumps (CMJ; jump height [JH]) and capillary blood samples (creatine kinase [CK]) were collected. After the last match of each day, further capillary samples were collected. Additional, CMJ were performed 12 and 60 h post-T1.
  
  
  RESULTS
  Player JH decreased from day 1 to day 2 during T1 (mean ± SD; -6.0 ± 5.4%; P=0.016), was reduced at 12 (-26.1 ± 5.0%; P<0.001) and 60 h post-T1 (-7.1 ± 4.8%; P=0.003) and remained lower, at am day 1 of T2 (-8.0 ± 6.0%; P=0.007), when compared with day 1 of T1. Player JH was lower on day 1 and 2 of T2, compared with T1 (P<0.05). CK concentrations were greater than baseline at all time points during each tournament (P<0.001); no between tournament differences in CK responses existed (P=0.302).
  
  
  CONCLUSIONS
  A single sevens tournament reduces NMF such that players are not fully recovered by the start of the second competition stage, however CK returns to baseline in-between and shows the same pattern across two consecutive tournaments.
authors: Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumberland Building, Northumbria University, Newcastle upon Tyne NE1 8ST, UK.
authors: Daniel J
authors: DJ
authors: West
authors: UK Sport, UK; Bangor University, Wales, UK.
authors: Christian J
authors: CJ
authors: Cook
authors: Department for Health, University of Bath, Bath BA2 7AY, UK.
authors: Keith A
authors: KA
authors: Stokes
authors: UK Sport, UK.
authors: Pete
authors: P
authors: Atkinson
authors: UK Sport, UK.
authors: Scott
authors: S
authors: Drawer
authors: Health and Sport Portfolio, Talbot Building, College of Engineering, Swansea University, Swansea SA2 8PP, UK.
authors: Richard M
authors: RM
authors: Bracken
authors: Health and Sport Portfolio, Talbot Building, College of Engineering, Swansea University, Swansea SA2 8PP, UK. Electronic address: l.kilduff@swansea.ac.uk.
authors: Liam P
authors: LP
authors: Kilduff
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries / Q000502:physiology*; D020127:Recovery of Function; D055815:Young Adult
keywords: Creatine kinase; Performance; Recovery