2007, Piran, Slovenia
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2007, Piran, Slovenia

2007, Piran, Slovenia 2007, Piran, Slovenia

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Environmental Ergonomics XII Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007 HNE), ubiquinated proteins, hypoxia markers such as HIF-1, PDK1 and m-Tor appear equally unchanged.. DISCUSSION Whereas lifelong hypoxia induces in Tibetans significant changes in muscle metabolism, altitude exposure over periods of 10-12 weeks does not induce in Caucasians a similar adaptive protein pattern. Probably, the found adaptational features of tibetan natives seem to require a much longer exposure time to develop if not a critical event. REFERENCES Marconi, C., M. Marzorati, B. Grassi, B. Basnyat,A. Colombini, B. Kayser and P. Cerretelli. Second generation Tibetan lowlanders acclimatize to high altitude more quickly than caucasians. J. Physiol. (Lond.) 556: 661-671, 2004. Marconi,C., Marzorati, M., D. Sciuto, A. Ferri, and P.Cerretelli. Economy of locomotion in high-altitude Tibetan migrants exposed to normoxia. J. Physiol. (Lond.) 569: 667-675, 2005. Gelfi,C., S. De Palma, M. Ripamonti, I. Eberini, R. Wait, A. Bajracharya, C. Marconi, A. Schneider, H. Hoppeler and P. Cerretelli. New aspects of altitude adaptation in Tibetans: a proteomic approach. The FASEB J. 18: 612- 614, 2004. Cerretelli, P., M. Ripamonti, S,. De Palma, A. Viganò, R. Wait, H. Howald, H. Hoppeler and C. Gelfi. Muscle proteins in Caucasian mountaineers after exposure to extreme hypoxia. (2007, submitted for publication) 80

Altitude Physiology IS INTERMITTENT HYPOXIC EXPOSURE AN ERGOGENIC METHOD? Petra Golja 1 , Matjaz Borovina 1 and Igor B. Mekjavic 2 1 University of Nova Gorica, Centre for Environmental and Sports Physiology, Vipavska 13, SI-5000 Nova Gorica, Slovenia 2 Institute Jozef Stefan, Department of Automation, Biocybernetics and Robotics, Jamova 39, SI-1000 Ljubljana, Slovenia Contact person: petra.golja@p-ng.si INTRODUCTION Intermittent hypoxic exposure, often referred to as intermittent hypoxic training (IHT), is a method used for altitude acclimatisation. The method assumes that a short duration hypoxic stimulus (inspiration of a hypoxic gas mixture) of high intensity (FiO2 corresponding to that of severe altitude above sea level) is supposed to evoke a similar level of altitude acclimatisation as a long sojourn at a moderate altitude. Thus, in contrast to standard acclimatisation techniques, which rely on prolonged exposures to moderate altitude, the method of IHT requires daily repetitive, short exposures to low-oxygen gas mixtures. The aim of the study was to test whether the use of IHT can induce altitude acclimatisation in cyclists and potentially improve their exercise performance. METHODS Twelve young, healthy cyclists of a similar level of training and at the beginning of their competitive period were divided into two groups, an acclimatisation group and a control group. The acclimatisation group performed IHT one hour daily, 5 days per week for 4 weeks. IHT consisted of repetitive exposures to a hypoxic gas mixture (FiO2 = 11.4 %, ≈ 4500 m) for 7 minutes, interrupted by 3 minutes of normoxia. During IHT subjects did not perform any physical activity. Hematological parameters (Hb, Hct, erithrocytes, reticulocytes, S-Fe, S-ferritin), oxygen saturation, maximal work load (as determined by an incremental cycle ergometry test performed at altitude (FiO2 = 13.3 %, ≈ 3000 m) and at sea level), heart rate, lactate, and ratings of perceived exertion were determined before and after the acclimatization procedure in both groups. RESULTS Mean (SD) oxygen saturation measured at the end of the fifth subsequent hypoxic exposure, was 84 (7) % on the first and 82 (3) % on the last day of IHT. Following the IHT procedure, no significant changes (p>0.05) in any of the monitored parameters were noted in either the control or the acclimatisation group (Table 1-2, Figure 1-3). 81

Environmental Ergonomics XII<br />

Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana <strong>2007</strong><br />

HNE), ubiquinated proteins, hypoxia markers such as HIF-1, PDK1 and m-Tor appear<br />

equally unchanged..<br />

DISCUSSION<br />

Whereas lifelong hypoxia induces in Tibetans significant changes in muscle<br />

metabolism, altitude exposure over periods of 10-12 weeks does not induce in<br />

Caucasians a similar adaptive protein pattern. Probably, the found adaptational<br />

features of tibetan natives seem to require a much longer exposure time to develop if<br />

not a critical event.<br />

REFERENCES<br />

Marconi, C., M. Marzorati, B. Grassi, B. Basnyat,A. Colombini, B. Kayser and P.<br />

Cerretelli. Second generation Tibetan lowlanders acclimatize to high altitude more<br />

quickly than caucasians. J. Physiol. (Lond.) 556: 661-671, 2004.<br />

Marconi,C., Marzorati, M., D. Sciuto, A. Ferri, and P.Cerretelli. Economy of<br />

locomotion in high-altitude Tibetan migrants exposed to normoxia. J. Physiol.<br />

(Lond.) 569: 667-675, 2005.<br />

Gelfi,C., S. De Palma, M. Ripamonti, I. Eberini, R. Wait, A. Bajracharya, C. Marconi,<br />

A. Schneider, H. Hoppeler and P. Cerretelli. New aspects of altitude adaptation in<br />

Tibetans: a proteomic approach. The FASEB J. 18: 612- 614, 2004.<br />

Cerretelli, P., M. Ripamonti, S,. De Palma, A. Viganò, R. Wait, H. Howald, H.<br />

Hoppeler and C. Gelfi. Muscle proteins in Caucasian mountaineers after exposure<br />

to extreme hypoxia. (<strong>2007</strong>, submitted for publication)<br />

80

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