Psycho-Physiological Responses to Repeated-Sprint Training in Normobaric Hypoxia and Normoxia

International audiencePURPOSE: We compared psycho-physiological responses to six repeated-sprint sessions in normobaric hypoxia (RSH) and normoxia (RSN) in team-sport athletes during a 2-wk ‘live high-train low’ training camp.METHODS: While residing under normobaric hypoxia (≥14 h.d-1; FiO2 14.5-14.2%), twenty-three lowland elite field hockey players performed, in addition to their usual training, six sessions (4 × 5 × 5-s maximal sprints; 25 s passive recovery; 5 min rest) under either normobaric hypoxia (FiO2 ~14.5%) or normoxia (FiO2 21%). Sprint 1 and 5 times, physiological strain [heart rate (HR), arterial oxyhemoglobin saturation (SpO2)] and perceptual responses (overall peripheral discomfort, difficulty breathing and lower-limb discomfort) were monitored.RESULTS: During the first session, HR increased across sets (P<0.001), independently of the conditions while SpO2 was globally lower (P<0.001) for RSH (averaged value: 91.9±1.2%) vs. RSN (96.9±0.6%). Thereafter, SpO2 and HR remained similar across sessions for each condition. While first sprint time remained similar, last sprint time and fatigue index significantly decreased across sets (P<0.01) and sessions (P<0.05) but not between conditions. Ratings of overall perceived discomfort, difficulty breathing and lower-limb discomfort were higher (P<0.05) in RSH vs. RSN at the first session. During subsequent sessions, overall perceived discomfort (time (P<0.001) and condition (P<0.05) effects), difficulty breathing (time effect; P<0.001) and lower-limb discomfort (condition (P<0.001) and interaction (P