Influences of normobaric hypoxia training on metabolic risk markers in human subjects

Item Type:	Article
Title:	Influences of normobaric hypoxia training on metabolic risk markers in human subjects
Creators Name:	Haufe, S. and Wiesner, S. and Engeli, S. and Luft, F.C. and Jordan, J.
Abstract:	PURPOSE: Endurance exercise and hypoxia regulate pathways that are crucial to glucose and lipid metabolism. We hypothesized that training under hypoxia results in similar or even greater metabolic improvement compared with exercise under normoxia at a lower workload. METHODS: We randomly assigned 20healthy men to single blind training under hypoxia (FiO2 = 15%) or normoxia (FiO2 = 21%). Subjects trained thrice weekly for 60min over a 4-wk period at a heart rate measured at 3 mmol.L lactate during pretraining exercise testing. Before and after the training period, we determined body composition, venous blood parameters, oral glucose tolerance, and blood pressure. Furthermore, we assessed oxygen uptake (Vdot;O2), lactate, and respiratory quotient, and heart rate (HR) during incremental exercise testing, both in hypoxia and in normoxia. Training workload was 1.39 +/- 0.2 W.kg in the hypoxia and 1.67 +/- 0.15 W.kg in the normoxia group (P< 0.001) with an identical training heart rate in both groups. RESULTS: Exercise capacity improved similarly with both interventions. With hypoxia training, body fat content, triglycerides, HOMA-Index, fasting insulin (P < 0.05), and area under the curve for insulin (P< 0.01) during the oral glucose tolerance test improved more than with the training in normoxia. We did not observe major changes in adipokine measurements. CONCLUSION: Endurance training in hypoxia over a 4-wk period elicits a similar or even better response in terms of cardiovascular and metabolic risk factors than endurance exercise in normoxia. The fact that workload and, therefore, mechanic strain can be reduced in hypoxia could be particularly beneficial in obese patients and in patients with orthopedic conditions.
Keywords:	Physiological Adaptation, Adipokines, Anoxia, Glucose Tolerance Test, Metabolism, Oxygen, Physical Exertion, Physical Fitness, Risk Factors, Single-Blind Method
Source:	Medicine and Science in Sports and Exercise
ISSN:	0195-9131
Publisher:	Lippincott Williams & Wilkins
Volume:	40
Number:	11
Page Range:	1939-1944
Date:	November 2008
Official Publication:	https://doi.org/10.1249/MSS.0b013e31817f1988
PubMed:	View item in PubMed

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