title: [Effects of intermittent normobaric hypoxia training on heart rate variability].
abstract: OBJECTIVE
  To observe the influences of intermittent normobaric hypoxia (INH) training on heart rate variability (HRV) under hypoxia.
  
  
  METHODS
  Eight subjects were trained with INH for 4 weeks (24 d), subjects' HRV level, recorded during exposure to hypoxia (10% O2) before and after the training, were compared and analyzed.
  
  
  RESULTS
  After the INH training, average of normal to normal Intervals (R-R), standard deviation of normal to normal Intervals (SDNN), total power (TP), high frequency (HF) and low frequency (LF) increased significantly during hypoxia (P<0.05 - P<0.001); normalized low frequency (LFn), normalized high frequency (HFn) and LF/HF showed no significant change.
  
  
  CONCLUSIONS
  1) INH training can increase subjects' HRV under hypoxia; 2) INH training can not only be used to increase the tolerance of hypoxia, but it is also good for increasing astronaut's flying tolerance under special environment.
authors.affiliation: Institute of Space Medico-Engineering, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Li-li
authors.initials: LL
authors.lastname: Lu
authors.forename: Zhang-huang
authors.initials: ZH
authors.lastname: Chen
authors.forename: Xiang-xin
authors.initials: XX
authors.lastname: Liu
authors.forename: Yong-zhi
authors.initials: YZ
authors.lastname: Li
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D000860:Hypoxia; D010101:Oxygen Consumption / Q000502:physiology*