title: Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trial.
abstract: BACKGROUND
  We investigated the effects of sleep deprivation with or without acute supplementation of caffeine or creatine on the execution of a repeated rugby passing skill.
  
  
  METHODS
  Ten elite rugby players completed 10 trials on a simple rugby passing skill test (20 repeats per trial), following a period of familiarisation. The players had between 7-9 h sleep on 5 of these trials and between 3-5 h sleep (deprivation) on the other 5. At a time of 1.5 h before each trial, they undertook administration of either: placebo tablets, 50 or 100 mg/kg creatine, 1 or 5 mg/kg caffeine. Saliva was collected before each trial and assayed for salivary free cortisol and testosterone.
  
  
  RESULTS
  Sleep deprivation with placebo application resulted in a significant fall in skill performance accuracy on both the dominant and non-dominant passing sides (p < 0.001). No fall in skill performance was seen with caffeine doses of 1 or 5 mg/kg, and the two doses were not significantly different in effect. Similarly, no deficit was seen with creatine administration at 50 or 100 mg/kg and the performance effects were not significantly different. Salivary testosterone was not affected by sleep deprivation, but trended higher with the 100 mg/kg creatine dose, compared to the placebo treatment (p = 0.067). Salivary cortisol was elevated (p = 0.001) with the 5 mg/kg dose of caffeine (vs. placebo).
  
  
  CONCLUSIONS
  Acute sleep deprivation affects performance of a simple repeat skill in elite athletes and this was ameliorated by a single dose of either caffeine or creatine. Acute creatine use may help to alleviate decrements in skill performance in situations of sleep deprivation, such as transmeridian travel, and caffeine at low doses appears as efficacious as higher doses, at alleviating sleep deprivation deficits in athletes with a history of low caffeine use. Both options are without the side effects of higher dose caffeine use.
authors.affiliation: UK Sport Council, 40 Bernard St London, UK.|Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, UK.|Department for Health, University of Bath, Bath, UK.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Cook
authors.affiliation: Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, UK.
authors.forename: Blair T
authors.initials: BT
authors.lastname: Crewther
authors.affiliation: Sport and Exercise Science Research Centre, Swansea University, Swansea, UK.
authors.forename: Liam P
authors.initials: LP
authors.lastname: Kilduff
authors.affiliation: UK Sport Council, 40 Bernard St London, UK.
authors.forename: Scott
authors.initials: S
authors.lastname: Drawer
authors.affiliation: Queensland Academy of Sport and Gold Coast SUNS, AFL Franchise Gold Coast, Brisbane, Australia.
authors.forename: Chris M
authors.initials: CM
authors.lastname: Gaviglio