title: Hypoxic training: Clinical benefits on cardiometabolic risk factors.
abstract: OBJECTIVE
  The main aim of this review was to evaluate the effectiveness of hypoxic training on the modulation of cardiometabolic risk factors.
  
  
  METHODS
  Literature review.
  
  
  METHODS
  An electronic search encompassing five databases (PUBMED, EMBASE, MEDLINE, CINAHL, and SPORTDiscus) was conducted. A total of 2138 articles were retrieved. After excluding non-relevant articles, duplications and outcomes not related to cardiometabolic risk factors, 25 articles were chosen for review.
  
  
  RESULTS
  Body weight and body composition were reported to be significantly improved when hypoxic training (≥1700 m) was used in conjunction with exercise regimes, at least three times a week, however extreme altitudes (>5000 m) resulted in a loss of fat-free muscle mass. Fasting blood glucose levels generally improved over time (≥21 days) at moderate levels of altitude (1500 m-3000 m), although reductions in blood glucose tolerance were observed when subjects were exposed to extreme hypoxia (>4000 m). Resting systolic and diastolic blood pressure levels improved as much as 26 mmHg and 13 mmHg respectively, with hypoxic training (1285 m-2650 m) in medicated, stable hypertensive subjects. Effects of hypoxic training when used in combination with exercise training on cholesterol levels were mixed. While there were improvements in total cholesterol (-4.2% to -30%) and low-density lipoprotein (-2.6% to -14.3%) reported as a result of hypoxic training, available evidence does not substantiate hypoxic training for the improvement of high-density lipoprotein and triglycerides.
  
  
  CONCLUSIONS
  In conclusion, hypoxic training may be used as an adjunct treatment to modify some cardiometabolic risk factors. Measurement of hypoxic load may be used to individualize and ascertain appropriate levels of hypoxic training.
authors.affiliation: Department of Physiotherapy, Tan Tock Seng Hospital, Singapore. Electronic address: Justin_WJ_WEE@ttsh.com.sg.
authors.forename: Justin
authors.initials: J
authors.lastname: Wee
authors.affiliation: Bond Institute of Health & Sport, Faculty of Health Science and Medicine, Bond University, Australia.
authors.forename: Mike
authors.initials: M
authors.lastname: Climstein
mesh_terms: D000399:Air Pressure; D000531:Altitude; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001823:Body Composition; D001835:Body Weight; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008055:Lipids / Q000097:blood; D010100:Oxygen; D064797:Physical Conditioning, Human / Q000379:methods* / Q000502:physiology*; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D008055:Lipids; D010100:Oxygen
keywords: Blood glucose; Blood pressure; Body composition; Body weight; Cholesterol