title: Exercise-Induced Hypoxaemia Developed at Sea-Level Influences Responses to Exercise at Moderate Altitude.
abstract: OBJECTIVE
  The aim of this study was to investigate the impact of exercise-induced hypoxaemia (EIH) developed at sea-level on exercise responses at moderate acute altitude.
  
  
  METHODS
  Twenty three subjects divided in three groups of individuals: highly trained with EIH (n = 7); highly trained without EIH (n = 8) and untrained participants (n = 8) performed two maximal incremental tests at sea-level and at 2,150 m. Haemoglobin O2 saturation (SpO2), heart rate, oxygen uptake (VO2) and several ventilatory parameters were measured continuously during the tests.
  
  
  RESULTS
  EIH athletes had a drop in SpO2 from 99 ± 0.8% to 91 ± 1.2% from rest to maximal exercise at sea-level, while the other groups did not exhibit a similar decrease. EIH athletes had a greater decrease in VO2max at altitude compared to non-EIH and untrained groups (-22 ± 7.9%, -16 ± 5.3% and -13 ± 9.4%, respectively). At altitude, non-EIH athletes had a similar drop in SpO2 as EIH athletes (13 ± 0.8%) but greater than untrained participants (6 ± 1.0%). EIH athletes showed greater decrease in maximal heart rate than non-EIH athletes at altitude (8 ± 3.3 bpm and 5 ± 2.9 bpm, respectively).
  
  
  CONCLUSIONS
  EIH athletes demonstrated specific cardiorespiratory response to exercise at moderate altitude compared to non-EIH athletes with a higher decrease in VO2max certainly due to the lower ventilator and HRmax responses. Thus EIH phenomenon developed at sea-level negatively impact performance and cardiorespiratory responses at acute moderate altitude despite no potentiated O2 desaturation.
authors: Laboratoire Européen Performance Santé Altitude-EA4604, Université de Perpignan Via Domitia, Font-Romeu, France.
authors: Anne-Fleur
authors: AF
authors: Gaston
authors: Laboratoire Européen Performance Santé Altitude-EA4604, Université de Perpignan Via Domitia, Font-Romeu, France.
authors: Fabienne
authors: F
authors: Durand
authors: Laboratoire Européen Performance Santé Altitude-EA4604, Université de Perpignan Via Domitia, Font-Romeu, France.|Facultat de Medicina, Universitat de Girona, Girona, Spain.
authors: Emma
authors: E
authors: Roca
authors: Laboratoire Européen Performance Santé Altitude-EA4604, Université de Perpignan Via Domitia, Font-Romeu, France.
authors: Grégory
authors: G
authors: Doucende
authors: Laboratoire Européen Performance Santé Altitude-EA4604, Université de Perpignan Via Domitia, Font-Romeu, France.
authors: Ilona
authors: I
authors: Hapkova
authors: Laboratoire Européen Performance Santé Altitude-EA4604, Université de Perpignan Via Domitia, Font-Romeu, France.|Facultat de Medicina, Universitat de Girona, Girona, Spain.
authors: Enric
authors: E
authors: Subirats
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000531:Altitude; D015444:Exercise; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption