Increased serum erythropoietin but not red cell production after 4 wk of intermittent hypobaric hypoxia (4,000–5,500 m)

2006 ◽  
Vol 101 (5) ◽  
pp. 1386-1393 ◽  
Author(s):  
Christopher J. Gore ◽  
Ferran A. Rodríguez ◽  
Martin J. Truijens ◽  
Nathan E. Townsend ◽  
James Stray-Gundersen ◽  
...  
Keyword(s):  
Transferrin Receptor ◽  
Hypobaric Hypoxia ◽  
Soluble Transferrin Receptor ◽  
Double Blind ◽  
Hypoxia Exposure ◽  
Intermittent Hypobaric Hypoxia ◽  
Collegiate Level ◽  
Norm Group ◽  
Hemoglobin Mass ◽  
Serum Erythropoietin

This study tested the hypothesis that athletes exposed to 4 wk of intermittent hypobaric hypoxia exposure (3 h/day, 5 days/wk at 4,000–5,500 m) or double-blind placebo increase their red blood cell volume (RCV) and hemoglobin mass (Hbmass) secondary to an increase in erythropoietin (EPO). Twenty-three collegiate level athletes were measured before (Pre) and after (Post) the intervention for RCV via Evans blue (EB) dye and in duplicate for Hbmassusing CO rebreathing. Hematological indexes including EPO, soluble transferrin receptor, and reticulocyte parameters were measured on 8–10 occasions spanning the intervention. The subjects were randomly divided among hypobaric hypoxia (Hypo, n = 11) and normoxic (Norm, n = 12) groups. Apart from doubling EPO concentration 3 h after hypoxia there was no increase in any of the measures for either Hypo or Norm groups. The mean change in RCV from Pre to Post for the Hypo group was 2.3% (95% confidence limits = −4.8 to 9.5%) and for the Norm group was −0.2% (−5.7 to 5.3%). The corresponding changes in Hbmasswere 1.0% (−1.3 to 3.3%) for Hypo and −0.3% (−2.6 to 3.1%) for Norm. There was good agreement between blood volume (BV) from EB and CO: EB BV = 1.03 × CO BV + 142, r2= 0.85, P < 0.0001. Overall, evidence from four independent techniques (RCV, Hbmass, reticulocyte parameters, and soluble transferrin receptor) suggests that INTERMITTENT HYPOBARIC HYPOXIA EXPOSURE did not accelerate erythropoiesis despite the increase in serum EPO.

Increased Hemoglobin Mass and VO2max With 10 h Nightly Simulated Altitude at 3000 m

2013 ◽  
Vol 8 (4) ◽  
pp. 366-372 ◽  
Author(s):  
Mitsuo Neya ◽  
Taisuke Enoki ◽  
Nao Ohiwa ◽  
Takashi Kawahara ◽  
Christopher J. Gore
Keyword(s):  
Oxygen Consumption ◽  
Confidence Interval ◽  
Total Dose ◽  
Transferrin Receptor ◽  
Soluble Transferrin Receptor ◽  
Simulated Altitude ◽  
Maximum Oxygen Consumption ◽  
Hemoglobin Mass ◽  
And Control ◽  
Serum Erythropoietin

Purpose:To quantify the changes of hemoglobin mass (Hbmass) and maximum oxygen consumption (VO2max) after 22 days training at 1300–1800 m combined with nightly exposure to 3000-m simulated altitude. We hypothesized that with simulated 3000-m altitude, an adequate beneficial dose could be as little as 10 h/24 h.Methods:Fourteen male collegiate runners were equally divided into 2 groups: altitude (ALT) and control (CON). Both groups spent 22 days at 1300–1800 m. ALT spent 10 h/night for 21 nights in simulated altitude (3000 m), and CON stayed at 1300 m. VO2max and Hbmass were measured twice before and once after the intervention. Blood was collected for assessment of percent reticulocytes (%retics), serum erythropoietin (EPO), ferritin, and soluble transferrin receptor (sTfR) concentrations.Results:Compared with CON there was an almost certain increase in absolute VO2max (8.6%, 90% confidence interval 4.8–12.6%) and a likely increase in absolute Hbmass (3.5%; 0.9–6.2%) at postintervention. The %retics were at least very likely higher in ALT than in CON throughout the 21 nights, and sTfR was also very likely higher in the ALT group until day 17. EPO of ALT was likely higher than that of CON on days 1 and 5 at altitude, whereas serum ferritin was likely lower in ALT than CON for most of the intervention.Conclusions:Together the combination of the natural and simulated altitude was a sufficient total dose of hypoxia to increase both Hbmass and VO2max.

The effect of intermittent hypobaric hypoxic exposure and sea level training on submaximal economy in well-trained swimmers and runners

2008 ◽  
Vol 104 (2) ◽  
pp. 328-337 ◽  
Author(s):  
Martin J. Truijens ◽  
Ferran A. Rodríguez ◽  
Nathan E. Townsend ◽  
James Stray-Gundersen ◽  
Christopher J. Gore ◽  
...  
Keyword(s):  
Sea Level ◽  
Repeated Measures ◽  
Hypobaric Hypoxia ◽  
Lactate Concentration ◽  
Hypoxic Exposure ◽  
Double Blind ◽  
Intermittent Hypobaric Hypoxia ◽  
Post Test ◽  
Double Blind Design ◽  
Level Training

To evaluate the effect of intermittent hypobaric hypoxia combined with sea level training on exercise economy, 23 well-trained athletes (13 swimmers, 10 runners) were assigned to either hypobaric hypoxia (simulated altitude of 4,000–5,500 m) or normobaric normoxia (0–500 m) in a randomized, double-blind design. Both groups rested in a hypobaric chamber 3 h/day, 5 days/wk for 4 wk. Submaximal economy was measured twice before (Pre) and after (Post) the treatment period using sport-specific protocols. Economy was estimated both from the relationship between oxygen uptake (V̇o2) and speed, and from the absolute V̇o2 at each speed using sport-specific protocols. V̇o2 was measured during the last 60 s of each (3–4 min) stage using Douglas bags. Ventilation (V̇e), heart rate (HR), and capillary lactate concentration ([La−]) were measured during each stage. Velocity at maximal V̇o2 (velocity at v̇o2max) was used as a functional indicator of changes in economy. The average V̇o2 for a given speed of the Pre values was used for Post test comparison using a two-way, repeated-measures ANOVA. Typical error of measurement of V̇o2 was 4.7% (95% confidence limits 3.6–7.1), 3.6% (2.8–5.4), and 4.2% (3.2–6.9) for speeds 1, 2, and 3, respectively. There was no change in economy within or between groups (ANOVA interaction P = 0.28, P = 0.23, and P = 0.93 for speeds 1, 2, and 3). No differences in submaximal HR, [La−], V̇e, or velocity at V̇o2max were found between groups. It is concluded that 4 wk of intermittent hypobaric hypoxia did not improve submaximal economy in this group of well-trained athletes.

scholarly journals Mechanisms of Cardiovascular Protection Associated with Intermittent Hypobaric Hypoxia Exposure in a Rat Model: Role of Oxidative Stress

2018 ◽  
Vol 19 (2) ◽  
pp. 366 ◽  
Author(s):  
Miguel Aguilar ◽  
Alejandro González-Candia ◽  
Jorge Rodríguez ◽  
Catalina Carrasco-Pozo ◽  
Daniel Cañas ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Rat Model ◽  
Hypobaric Hypoxia ◽  
Cardiovascular Protection ◽  
Hypoxia Exposure ◽  
Intermittent Hypobaric Hypoxia

The Effect of Intermittent Hypobaric Hypoxia Exposure on Reduced-Glutathione Level in Rat Lung and Renal Tissues

2018 ◽  
Vol 24 (8) ◽  
pp. 6249-6251
Author(s):  
N. S Hardiany ◽  
A. A Asa ◽  
D Safirina ◽  
W Mulyawan
Keyword(s):  
Hypobaric Hypoxia ◽  
Reduced Glutathione ◽  
Renal Tissue ◽  
Rat Lung ◽  
Sprague Dawley ◽  
Hypoxia Exposure ◽  
Intermittent Hypobaric Hypoxia ◽  
Sprague Dawley Rats ◽  
Adaptation Response ◽  
Ellman’S Method

Hypobaric hypoxia is basically a hypoxia condition experienced in high altitude commonly during flight, that increase reactive oxygen species (ROS). When hypoxia hypobaric does not undergo continuation or in other word, intermittent, it will cause adaptation response in a form of protection mode into ROS. Moreover, ROS could be eliminated by reduced-glutathione (GSH) as an endogenous non enzymatic antioxidant. Therefore, the aim of this study was to analyze the effects of intermittent hypobaric hypoxia exposure on GSH level in rat lung and renal tissue. Lung and renal samples were collected from 6–8 weeks old male Sprague-Dawley rats weighing 150–200 g, previously exposed 1–4 times to intermittent hypobaric hypoxia in 35,000 ft (1 minute), 25.000 ft (5 minute) and 18,000 ft altitude (25 minute). Afterwards, GSH level was calculated from lung and renal extracts using the Ellman’s method. In lung tissues, GSH level was decreased in hypoxia 1×, 2×, 3×, 4× treatment, and were significant between the control–hypoxia 3×, control–hypoxia 4×, hypoxia 1×–hypoxia 3× and hypoxia 1×–hypoxia 4×. On the contrary, GSH level was increased in renal tissues on hypoxia 1× and hypoxia 2× treatment compared to control. Nevertheless, GSH level was decreased after 3× treatment and found almost stabilized at 4× treatment of hypoxia in renal tissues. Intermittent hypobaric hypoxia exposure affect GSH in rat lung and renal tissues with varying level as an adaptive response system.

Intermittent hypobaric hypoxia combined with aerobic exercise improves muscle morphofunctional recovery after eccentric exercise to exhaustion in trained rats

2017 ◽  
Vol 122 (3) ◽  
pp. 580-592 ◽  
Author(s):  
D. Rizo-Roca ◽  
J. G. Ríos-Kristjánsson ◽  
C. Núñez-Espinosa ◽  
E. Santos-Alves ◽  
I. O. Gonçalves ◽  
...  
Keyword(s):  
Aerobic Exercise ◽  
Muscle Damage ◽  
Eccentric Exercise ◽  
Hypobaric Hypoxia ◽  
Citrate Synthase ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Cross Sectional ◽  
Hypoxia Exposure ◽  
Intermittent Hypobaric Hypoxia

Unaccustomed eccentric exercise leads to muscle morphological and functional alterations, including microvasculature damage, the repair of which is modulated by hypoxia. We present the effects of intermittent hypobaric hypoxia and exercise on recovery from eccentric exercise-induced muscle damage (EEIMD). Soleus muscles from trained rats were excised before (CTRL) and 1, 3, 7, and 14 days after a double session of EEIMD protocol. A recovery treatment consisting of one of the following protocols was applied 1 day after the EEIMD: passive normobaric recovery (PNR), a 4-h daily exposure to passive hypobaric hypoxia at 4,000 m (PHR), or hypobaric hypoxia exposure followed by aerobic exercise (AHR). EEIMD produced an increase in the percentage of abnormal fibers compared with CTRL, and it affected the microvasculature by decreasing capillary density (CD, capillaries per mm2) and the capillary-to-fiber ratio (CF). After 14 days, AHR exhibited CD and CF values similar to those of CTRL animals (789 and 3.30 vs. 746 and 3.06) and significantly higher than PNR (575 and 2.62) and PHR (630 and 2.92). Furthermore, VEGF expression showed a significant 43% increase in AHR when compared with PNR. Moreover, after 14 days, the muscle fibers in AHR had a more oxidative phenotype than the other groups, with significantly smaller cross-sectional areas (AHR, 3,745; PNR, 4,502; and PHR, 4,790 µm2), higher citrate synthase activity (AHR, 14.8; PNR, 13.1; and PHR, 12 µmol·min−1·mg−1) and a significant 27% increment in PGC-1α levels compared with PNR. Our data show that hypoxia combined with exercise attenuates or reverses the morphofunctional alterations induced by EEIMD. NEW & NOTEWORTHY Our study provides new insights into the use of intermittent hypobaric hypoxia combined with exercise as a strategy to recover muscle damage induced by eccentric exercise. We analyzed the effects of hypobaric exposure combined with aerobic exercise on histopathological features of muscle damage, fiber morphofunctionality, capillarization, angiogenesis, and the oxidative capacity of damaged soleus muscle. Most of these parameters were improved after a 2-wk protocol of intermittent hypobaric hypoxia combined with aerobic exercise.

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