title: Impact of Altitude on Power Output during Cycling Stage Racing.
abstract: OBJECTIVE
  The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour.
  
  
  METHODS
  Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (<1000 m, 1000-2000, 2000-3000 and >3000 m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin.
  
  
  RESULTS
  Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level.
  
  
  CONCLUSIONS
  A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.
authors.affiliation: Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia.|Physiology, Australian Institute of Sport, Canberra, Australia.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Garvican-Lewis
authors.affiliation: Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia.|Physiology, Australian Institute of Sport, Canberra, Australia.
authors.forename: Bradley
authors.initials: B
authors.lastname: Clark
authors.affiliation: Physiology, Australian Institute of Sport, Canberra, Australia.
authors.forename: David T
authors.initials: DT
authors.lastname: Martin
authors.affiliation: Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
authors.forename: Yorck Olaf
authors.initials: YO
authors.lastname: Schumacher
authors.affiliation: Cycling Australia, Adelaide, Australia.
authors.forename: Warren
authors.initials: W
authors.lastname: McDonald
authors.affiliation: Cycling Australia, Adelaide, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Stephens
authors.affiliation: Qinghai Institute of Sport Science, Duoba, China.
authors.forename: Fuhai
authors.initials: F
authors.lastname: Ma
authors.affiliation: Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia.
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Thompson
authors.affiliation: Physiology, Australian Institute of Sport, Canberra, Australia.|Exercise Physiology Laboratory, Flinders University, Adelaide, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gore
authors.affiliation: Physiology, Australian Institute of Sport, Canberra, Australia.|Edith Cowan University, Perth, Australia.
authors.forename: Paolo
authors.initials: P
authors.lastname: Menaspà
mesh_terms: D000531:Altitude; D056352:Athletes; D001642:Bicycling / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D060106:Lakes; D008297:Male