title: "Live High-Train Low and High" Hypoxic Training Improves Team-Sport Performance.
abstract: OBJECTIVE
  This study aims to investigate physical performance and hematological changes in 32 elite male team-sport players after 14 d of "live high-train low" (LHTL) training in normobaric hypoxia (≥14 h·d at 2800-3000 m) combined with repeated-sprint training (six sessions of four sets of 5 × 5-s sprints with 25 s of passive recovery) either in normobaric hypoxia at 3000 m (LHTL + RSH, namely, LHTLH; n = 11) or in normoxia (LHTL + RSN, namely, LHTL; n = 12) compared with controlled "live low-train low" (LLTL; n = 9) training.
  
  
  METHODS
  Before (Pre), immediately after (Post-1), and 3 wk after (Post-2) the intervention, hemoglobin mass (Hbmass) was measured in duplicate [optimized carbon monoxide (CO) rebreathing method], and vertical jump, repeated-sprint (8 × 20 m-20 s recovery), and Yo-Yo Intermittent Recovery level 2 (YYIR2) performances were tested.
  
  
  RESULTS
  Both hypoxic groups similarly increased their Hbmass at Post-1 and Post-2 in reference to Pre (LHTLH: +4.0%, P < 0.001 and +2.7%, P < 0.01; LHTL: +3.0% and +3.0%, both P < 0.001), whereas no change occurred in LLTL. Compared with Pre, YYIR2 performance increased by ∼21% at Post-1 (P < 0.01) and by ∼45% at Post-2 (P < 0.001), with no difference between the two intervention groups (vs no change in LLTL). From Pre to Post-1, cumulated sprint time decreased in LHTLH (-3.6%, P < 0.001) and LHTL (-1.9%, P < 0.01), but not in LLTL (-0.7%), and remained significantly reduced at Post-2 (-3.5%, P < 0.001) in LHTLH only. Vertical jump performance did not change.
  
  
  CONCLUSIONS
  "Live high-train low and high" hypoxic training interspersed with repeated sprints in hypoxia for 14 d (in season) increases the Hbmass, YYIR2 performance, and repeated-sprint ability of elite field team-sport players, with benefits lasting for at least 3 wk postintervention.
authors: 1ISSUL, Institute of Sports Sciences, University of Lausanne, Lausanne, SWITZERLAND; 2Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, SWITZERLAND; 3Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, SWITZERLAND; 4Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, BELGIUM; and 5Athlete Health and Performance Research Center, ASPETAR, Qatar Orthopedic and Sports Medicine Hospital, Doha, QATAR.
authors: Franck
authors: F
authors: Brocherie
authors: Grégoire P
authors: GP
authors: Millet
authors: Anna
authors: A
authors: Hauser
authors: Thomas
authors: T
authors: Steiner
authors: Julien
authors: J
authors: Rysman
authors: Jon P
authors: JP
authors: Wehrlin
authors: Olivier
authors: O
authors: Girard
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000531:Altitude; D054874:Athletic Performance / Q000502:physiology*; D004311:Double-Blind Method; D006339:Heart Rate; D006688:Hockey / Q000502:physiology; D006801:Humans; D000860:Hypoxia; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism; D010806:Physical Education and Training / Q000379:methods*; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins