AUTHOR=Saugy Jonas J. , Schmitt Laurent , Hauser Anna , Constantin Guillaume , Cejuela Roberto , Faiss Raphael , Wehrlin Jon P. , Rosset Jérémie , Robinson Neil , Millet Grégoire P. 

TITLE=Same Performance Changes after Live High-Train Low in Normobaric vs. Hypobaric Hypoxia

JOURNAL=Frontiers in Physiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2016.00138

DOI=10.3389/fphys.2016.00138

ISSN=1664-042X

ABSTRACT=<p><bold>Purpose:</bold> We investigated the changes in physiological and performance parameters after a Live High-Train Low (LHTL) altitude camp in normobaric (NH) or hypobaric hypoxia (HH) to reproduce the actual training practices of endurance athletes using a crossover-designed study.</p><p><bold>Methods:</bold> Well-trained triathletes (<italic>n</italic> = 16) were split into two groups and completed two 18-day LTHL camps during which they trained at 1100–1200 m and lived at 2250 m (P<sub><italic>i</italic></sub>O<sub>2</sub> = 111.9 ± 0.6 vs. 111.6 ± 0.6 mmHg) under NH (hypoxic chamber; F<sub>i</sub>O<sub>2</sub> 18.05 ± 0.03%) or HH (real altitude; barometric pressure 580.2 ± 2.9 mmHg) conditions. The subjects completed the NH and HH camps with a 1-year washout period. Measurements and protocol were identical for both phases of the crossover study. Oxygen saturation (S<sub><italic>p</italic></sub>O<sub>2</sub>) was constantly recorded nightly. P<sub><italic>i</italic></sub>O<sub>2</sub> and training loads were matched daily. Blood samples and VO<sub>2<italic>max</italic></sub> were measured before (Pre-) and 1 day after (Post-1) LHTL. A 3-km running-test was performed near sea level before and 1, 7, and 21 days after training camps.</p><p><bold>Results:</bold> Total hypoxic exposure was lower for NH than for HH during LHTL (230 vs. 310 h; <italic>P</italic> &lt; 0.001). Nocturnal S<sub><italic>p</italic></sub>O<sub>2</sub> was higher in NH than in HH (92.4 ± 1.2 vs. 91.3 ± 1.0%, <italic>P</italic> &lt; 0.001). VO<sub>2<italic>max</italic></sub> increased to the same extent for NH and HH (4.9 ± 5.6 vs. 3.2 ± 5.1%). No difference was found in hematological parameters. The 3-km run time was significantly faster in both conditions 21 days after LHTL (4.5 ± 5.0 vs. 6.2 ± 6.4% for NH and HH), and no difference between conditions was found at any time.</p><p><bold>Conclusion:</bold> Increases in VO<sub>2<italic>max</italic></sub> and performance enhancement were similar between NH and HH conditions.</p>