Effect of hypoxic training on inflammatory and metabolic risk factors: a crossover study in healthy subjects

Abstract

The purpose of this study was to investigate the influence of hypoxic physical exercise on metabolic syndrome (MS) risk markers and high‐sensitivity C‐reactive protein (CRP) and to compare its effects on preperitoneal fat, arterial stiffness, and several blood parameters related to MS to those of a control group who trained under normoxic conditions. Fourteen healthy men were examined. Participants performed treadmill exercise 3 days per week for 4 weeks, under either normobaric hypoxic or normobaric normoxic conditions, for 50 min (including a 5‐min warm‐up and 5‐min cool down) after a 30‐min rest period. Exercise was performed at a heart rate (HR) corresponding to 60% of the HR at each individual's maximum oxygen uptake. Training under the different environmental conditions was performed 4 months apart to ensure a sufficient washout period. Waist circumference, preperitoneal fat thickness, brachial‐ankle pulse wave velocity, and high‐sensitivity CRP after training were significantly lower in the hypoxic group than in the normoxic group. Our results suggest that regular short‐term hypoxic training may more effectively reduce arterial stiffness, and thus prevent arteriosclerosis, compared to training performed at a similar exercise intensity under normoxic conditions.

Influences of Short-Term Normobaric Hypoxic Training on Metabolic Syndrome-Related Markers in Overweight and Normal-Weight Men

“…20 In a crossover study by Shi et al involving 4 weeks of aerobic exercise in a 2500-m hypoxic environment for male college students, PWV was signifi cantly lower in the hypoxic group after training. 5 In addition, Nishiwaki et al reported that hypoxic training increased fl ow-mediated vasodilation (FMD) (an indicator of increased blood fl ow) and reduced PWV, similar to the results of this study. 21 Katayama et al reported that aerobic exercise improved vascular endothelial function to a greater extent in a hypoxic environment than in a sea-level environment.…”

“…Shi et al examined the eff ect of hypoxic training on high-sensitivity C-reactive protein (hs-CRP) levels, an infl ammatory marker, in healthy adult males and reported that hs-CRP levels were signifi cantly lower in the hypoxic group than in the control group after the training. 5 Therefore, hypoxic training may have positive, anti-infl ammatory eff ects on metabolic syndrome-related factors.…”

“…based on the protocol of Shi et al 5 They trained on a treadmill 3 days per week for 4 weeks, under either normobaric hypoxic (15.4% O 2 , equivalent to an altitude of 2500 m) or normobaric normoxic (20.9% O 2 , equivalent to sea level) conditions for 50 min (including 5-minute warm-up and cool-down periods). In both environmental conditions, a 30-minute rest period preceded and followed each exercise session.…”

The effects of exercise training under mild hypoxic conditions on body composition and circulating adiponectin in postmenopausal women

“…Because lean body mass did not change significantly in either group, the reduction of body mass identified after hypoxic training primarily results from the reduction of body fat. Our results also support previous findings that hypoxic exercise training induces reductions of body mass and/or body fat (Haufe et al ., ; Netzer et al ., ; Wiesner et al ., ; Shi et al ., ). Therefore, the present data suggest that exercise training under mild hypoxic conditions could more effectively reduce body fat even in postmenopausal women than exercise training in normoxia.…”

“…In particular, several reports have demonstrated that exercise training under mild‐to‐moderate hypoxic conditions (i.e. approximately 2000–2700 m above sea level, 3–4 days week −1 , for 4–8 weeks) induces a reduction of body mass and fat and an increase in insulin sensitivity (Haufe et al ., ; Netzer et al ., ; Wiesner et al ., ; Shi et al ., ). We have also provided evidence that aquatic exercise training [i.e.…”