title: Live-high train-low improves repeated time-trial and Yo-Yo IR2 performance in sub-elite team-sport athletes.
abstract: OBJECTIVE
  To determine the efficacy of live-high train-low on team-sport athlete physical capacity and the time-course for adaptation.
  
  
  METHODS
  Pre-post parallel-groups.
  
  
  METHODS
  Fifteen Australian footballers were matched for Yo-Yo Intermittent recovery test level 2 (Yo-YoIR2) performance and assigned to LHTL (n=7) or control (Con; n=8). LHTL spent 19 nights (3×5 nights, 1×4 nights, each block separated by 2 nights at sea level) at 3000-m simulated altitude (FIO2: 0.142). Yo-Yo IR2 was performed pre and post 5, 15, and 19 nights. A 2- and 1-km time-trial (TT) was performed pre and post intervention. Haemoglobin mass (Hbmass) was measured in LHTL after 5, 10, 15, and 19 nights. A contemporary statistical approach using effect size, confidence limits, and magnitude-based inferences was used to measure changes between groups.
  
  
  RESULTS
  Compared to pre, Hbmasswas possibly higher after 15 (3.8%, effect size (ES) 0.19, 90% confidence limits 0.05-0.33) and very likely higher after 19 nights (6.7%, 0.35, 0.10; 0.52). For Yo-Yo IR2, LHTL group change was not meaningfully different to Con after 5 nights, possibly greater after 15 (10.2%, 0.37, -0.29; 1.04), and likely greater after 19 nights (13.5%, 0.49, -0.16; 1.14). Both groups improved 2-km TT, with LHTL improvement possibly higher than CON (1.9%, 0.22, -0.18; 0.62). Only LHTL improved 1-km TT, with LHTL improvement likely greater than CON (4.6%, 0.56, -0.08; 1.04).
  
  
  CONCLUSIONS
  Fifteen nights of LHTL was possibly effective, while 19 nights was effective at increasing Hbmass, Yo-Yo IR2 and repeated TT performance more than sea-level training.
authors.affiliation: Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Australia; Western Bulldogs Football Club, Australia.
authors.forename: Mathew W H
authors.initials: MWH
authors.lastname: Inness
authors.affiliation: Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Australia; Département de Kinésiologie, Université Laval, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Billaut
authors.affiliation: Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Australia. Electronic address: robert.aughey@vu.edu.au.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Aughey
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000531:Altitude; D054874:Athletic Performance / Q000502:physiology*; D001315:Australia; D016022:Case-Control Studies; D005538:Football; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D010806:Physical Education and Training / Q000379:methods*; D010809:Physical Fitness / Q000502:physiology*; D012420:Running / Q000502:physiology; D055815:Young Adult
chemical_list: D006454:Hemoglobins
keywords: Altitude training aerobic; Hypoxia; Team sport