title: Does Elite Sport Degrade Sleep Quality? A Systematic Review.
abstract: BACKGROUND
  Information on sleep quality and insomnia symptomatology among elite athletes remains poorly systematised in the sports science and medicine literature. The extent to which performance in elite sport represents a risk for chronic insomnia is unknown.
  
  
  OBJECTIVE
  The purpose of this systematic review was to profile the objective and experienced characteristics of sleep among elite athletes, and to consider relationships between elite sport and insomnia symptomatology.
  
  
  METHODS
  Studies relating to sleep involving participants described on a pre-defined continuum of 'eliteness' were located through a systematic search of four research databases: SPORTDiscus, PubMed, Science Direct and Google Scholar, up to April 2016. Once extracted, studies were categorised as (1) those mainly describing sleep structure/patterns, (2) those mainly describing sleep quality and insomnia symptomatology and (3) those exploring associations between aspects of elite sport and sleep outcomes.
  
  
  RESULTS
  The search returned 1676 records. Following screening against set criteria, a total of 37 studies were identified. The quality of evidence reviewed was generally low. Pooled sleep quality data revealed high levels of sleep complaints in elite athletes. Three risk factors for sleep disturbance were broadly identified: (1) training, (2) travel and (3) competition.
  
  
  CONCLUSIONS
  While acknowledging the limited number of high-quality evidence reviewed, athletes show a high overall prevalence of insomnia symptoms characterised by longer sleep latencies, greater sleep fragmentation, non-restorative sleep, and excessive daytime fatigue. These symptoms show marked inter-sport differences. Two underlying mechanisms are implicated in the mediation of sport-related insomnia symptoms: pre-sleep cognitive arousal and sleep restriction.
authors.affiliation: Physiology Department, English Institute of Sport, Bisham, Nr. Marlow, SL7 1RR, UK. luke.gupta@eis2win.co.uk.|Clinical Sleep Research Unit, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK. luke.gupta@eis2win.co.uk.
authors.forename: Luke
authors.identifier: http://orcid.org/0000-0002-8319-0596
authors.initials: L
authors.lastname: Gupta
authors.affiliation: Clinical Sleep Research Unit, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK.
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
authors.affiliation: Physiology Department, English Institute of Sport, Bisham, Nr. Marlow, SL7 1RR, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Gilchrist
mesh_terms: D056352:Athletes; D005221:Fatigue / Q000209:etiology*; D006801:Humans; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders; D012893:Sleep Wake Disorders; D013177:Sports