title: Adding heat to the live-high train-low altitude model: a practical insight from professional football.
abstract: OBJECTIVE
  To examine with a parallel group study design the performance and physiological responses to a 14-day off-season 'live high-train low in the heat' training camp in elite football players.
  
  
  METHODS
  Seventeen professional Australian Rules Football players participated in outdoor football-specific skills (32 ± 1°C, 11.5 h) and indoor strength (23 ± 1°C, 9.3 h) sessions and slept (12 nights) and cycled indoors (4.3 h) in either normal air (NORM, n=8) or normobaric hypoxia (14 ± 1 h/day, FiO2 15.2-14.3%, corresponding to a simulated altitude of 2500-3000 m, hypoxic (HYP), n=9). They completed the Yo-Yo Intermittent Recovery level 2 (Yo-YoIR2) in temperate conditions (23 ± 1°C, normal air) precamp (Pre) and postcamp (Post). Plasma volume (PV) and haemoglobin mass (Hb(mass)) were measured at similar times and 4 weeks postcamp (4WPost). Sweat sodium concentration ((Na(+))(sweat)) was measured Pre and Post during a heat-response test (44°C).
  
  
  RESULTS
  Both groups showed very large improvements in Yo-YoIR2 at Post (+44%; 90% CL 38, 50), with no between-group differences in the changes (-1%; -9, 9). Postcamp, large changes in PV (+5.6%; -1.8, 5.6) and (Na(+))sweat (-29%; -37, -19) were observed in both groups, while Hb(mass) only moderately increased in HYP (+2.6%; 0.5, 4.5). At 4WPost, there was a likely slightly greater increase in Hb(mass) (+4.6%; 0.0, 9.3) and PV (+6%; -5, 18, unclear) in HYP than in NORM.
  
  
  CONCLUSIONS
  The combination of heat and hypoxic exposure during sleep/training might offer a promising 'conditioning cocktail' in team sports.
authors.affiliation: Physiology Unit, Football Performance and Science Department, ASPIRE, Academy for Sports Excellence, , Doha, Qatar.
authors.forename: M
authors.initials: M
authors.lastname: Buchheit
authors.forename: S
authors.initials: S
authors.lastname: Racinais
authors.forename: J
authors.initials: J
authors.lastname: Bilsborough
authors.forename: J
authors.initials: J
authors.lastname: Hocking
authors.forename: A
authors.initials: A
authors.lastname: Mendez-Villanueva
authors.forename: P C
authors.initials: PC
authors.lastname: Bourdon
authors.forename: S
authors.initials: S
authors.lastname: Voss
authors.forename: S
authors.initials: S
authors.lastname: Livingston
authors.forename: R
authors.initials: R
authors.lastname: Christian
authors.forename: J
authors.initials: J
authors.lastname: Périard
authors.forename: J
authors.initials: J
authors.lastname: Cordy
authors.forename: A J
authors.initials: AJ
authors.lastname: Coutts
mesh_terms: D000064:Acclimatization / Q000502:physiology; D000531:Altitude; D054874:Athletic Performance / Q000502:physiology; D001274:Atmospheric Pressure; D001315:Australia; D001810:Blood Volume / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005538:Football / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology; D012420:Running / Q000502:physiology; D012890:Sleep / Q000502:physiology
chemical_list: D006454:Hemoglobins
keywords: Aerobic fitness/Vo2 Max; Altitude; Dehydration; Thermoregulation; Training