title: The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600).
abstract: BACKGROUND
  Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives.
  
  
  METHODS
  Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were members of a Bolivian under-20 club team (n=12). Teams participated in an 18-day (19 nights) training camp in Bolivia, with 6 nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was assessed on every day/night using activity monitors.
  
  
  RESULTS
  The Australians' sleep was shorter, and of poorer quality, on the first night at altitude compared with sea level. Sleep quality returned to normal by the end of the first week at altitude, but sleep quantity had still not stabilised at its normal level after 2 weeks. The quantity and quality of sleep obtained by the Bolivians was similar, or greater, on all nights at altitude compared with sea level. The Australians tended to obtain more sleep than the Bolivians at sea level and altitude, but the quality of the Bolivians' sleep tended to be better than that of the Australians at altitude.
  
  
  CONCLUSIONS
  Exposure to high altitude causes acute and chronic disruption to the sleep of elite athletes who are sea-level natives, but it does not affect the sleep of elite athletes who are high-altitude natives.
authors.affiliation: Appleton Institute for Behavioural Science, Central Queensland University, , Adelaide, Australia.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Roach
authors.forename: Walter F
authors.initials: WF
authors.lastname: Schmidt
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Aughey
authors.forename: Pitre C
authors.initials: PC
authors.lastname: Bourdon
authors.forename: Rudy
authors.initials: R
authors.lastname: Soria
authors.forename: Jesus C Jimenez
authors.initials: JC
authors.lastname: Claros
authors.forename: Laura A
authors.initials: LA
authors.lastname: Garvican-Lewis
authors.forename: Martin
authors.initials: M
authors.lastname: Buchheit
authors.forename: Ben M
authors.initials: BM
authors.lastname: Simpson
authors.forename: Kristal
authors.initials: K
authors.lastname: Hammond
authors.forename: Marlen
authors.initials: M
authors.lastname: Kley
authors.forename: Nadine
authors.initials: N
authors.lastname: Wachsmuth
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gore
authors.forename: Charli
authors.initials: C
authors.lastname: Sargent
mesh_terms: D000293:Adolescent; D000531:Altitude; D001315:Australia / Q000208:ethnology; D001838:Bolivia / Q000208:ethnology; D006801:Humans; D008297:Male; D012890:Sleep / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D014195:Travel
keywords: Altitude; Elite performance; Physiology; Soccer