title: Prooxidant/Antioxidant Balance in Hypoxia: A Cross-Over Study on Normobaric vs. Hypobaric "Live High-Train Low".
abstract: "Live High-Train Low" (LHTL) training can alter oxidative status of athletes. This study compared prooxidant/antioxidant balance responses following two LHTL protocols of the same duration and at the same living altitude of 2250 m in either normobaric (NH) or hypobaric (HH) hypoxia. Twenty-four well-trained triathletes underwent the following two 18-day LHTL protocols in a cross-over and randomized manner: Living altitude (PIO2 = 111.9 ± 0.6 vs. 111.6 ± 0.6 mmHg in NH and HH, respectively); training "natural" altitude (~1000-1100 m) and training loads were precisely matched between both LHTL protocols. Plasma levels of oxidative stress [advanced oxidation protein products (AOPP) and nitrotyrosine] and antioxidant markers [ferric-reducing antioxidant power (FRAP), superoxide dismutase (SOD) and catalase], NO metabolism end-products (NOx) and uric acid (UA) were determined before (Pre) and after (Post) the LHTL. Cumulative hypoxic exposure was lower during the NH (229 ± 6 hrs.) compared to the HH (310 ± 4 hrs.; P<0.01) protocol. Following the LHTL, the concentration of AOPP decreased (-27%; P<0.01) and nitrotyrosine increased (+67%; P<0.05) in HH only. FRAP was decreased (-27%; P<0.05) after the NH while was SOD and UA were only increased following the HH (SOD: +54%; P<0.01 and UA: +15%; P<0.01). Catalase activity was increased in the NH only (+20%; P<0.05). These data suggest that 18-days of LHTL performed in either NH or HH differentially affect oxidative status of athletes. Higher oxidative stress levels following the HH LHTL might be explained by the higher overall hypoxic dose and different physiological responses between the NH and HH.
authors.affiliation: Department of Automation, Biocybernetics and Robotics, "Jozef Stefan" Institute, Ljubljana, Slovenia.
authors.forename: Tadej
authors.initials: T
authors.lastname: Debevec
authors.affiliation: Center of Research and Innovation on Sports, University Claude Bernard Lyon 1, Villeurbanne, France; Institut Universitaire de France, Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pialoux
authors.affiliation: ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Saugy
authors.affiliation: ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; National School of Mountain Sports/National Ski-Nordic Centre, Prémanon, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Schmitt
authors.affiliation: Departmental Section of Physical Education and Sports, University of Alicante, Alicante, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cejuela
authors.affiliation: Center of Research and Innovation on Sports, University Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Mury
authors.affiliation: Center of Research and Innovation on Sports, University Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Ehrström
authors.affiliation: ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Faiss
authors.affiliation: ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
authors.forename: Grégoire P
authors.initials: GP
authors.lastname: Millet
mesh_terms: D000328:Adult; D062107:Advanced Oxidation Protein Products / Q000097:blood; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008297:Male; D018384:Oxidative Stress; D010809:Physical Fitness; D013482:Superoxide Dismutase / Q000097:blood; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood; D014527:Uric Acid / Q000097:blood
chemical_list: D062107:Advanced Oxidation Protein Products; D014527:Uric Acid; C002744:3-nitrotyrosine; D014443:Tyrosine; D013482:Superoxide Dismutase