Exercise training in normobaric hypoxia in endurance runners. III. Muscular adjustments of selected gene transcripts

Zoll, Joffrey; Ponsot, Elodie; Dufour, Stéphane; Doutreleau, Stéphane; Ventura-Clapier, Renée; Vogt, Michael; Hoppeler, Hans; Richard, Ruddy; Flück, Martin (2006). Exercise training in normobaric hypoxia in endurance runners. III. Muscular adjustments of selected gene transcripts. Journal of applied physiology, 100(4), pp. 1258-66. Bethesda, Md.: American Physiological Society 10.1152/japplphysiol.00359.2005

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We hypothesized that specific muscular transcript level adaptations participate in the improvement of endurance performances following intermittent hypoxia training in endurance-trained subjects. Fifteen male high-level, long-distance runners integrated a modified living low-training high program comprising two weekly controlled training sessions performed at the second ventilatory threshold for 6 wk into their normal training schedule. The athletes were randomly assigned to either a normoxic (Nor) (inspired O2 fraction = 20.9%, n = 6) or a hypoxic group exercising under normobaric hypoxia (Hyp) (inspired O2 fraction = 14.5%, n = 9). Oxygen uptake and speed at second ventilatory threshold, maximal oxygen uptake (VO2 max), and time to exhaustion (Tlim) at constant load at VO2 max velocity in normoxia and muscular levels of selected mRNAs in biopsies were determined before and after training. VO2 max (+5%) and Tlim (+35%) increased specifically in the Hyp group. At the molecular level, mRNA concentrations of the hypoxia-inducible factor 1alpha (+104%), glucose transporter-4 (+32%), phosphofructokinase (+32%), peroxisome proliferator-activated receptor gamma coactivator 1alpha (+60%), citrate synthase (+28%), cytochrome oxidase 1 (+74%) and 4 (+36%), carbonic anhydrase-3 (+74%), and manganese superoxide dismutase (+44%) were significantly augmented in muscle after exercise training in Hyp only. Significant correlations were noted between muscular mRNA levels of monocarboxylate transporter-1, carbonic anhydrase-3, glucose transporter-4, and Tlim only in the group of athletes who trained in hypoxia (P < 0.05). Accordingly, the addition of short hypoxic stress to the regular endurance training protocol induces transcriptional adaptations in skeletal muscle of athletic subjects. Expressional adaptations involving redox regulation and glucose uptake are being recognized as a potential molecular pathway, resulting in improved endurance performance in hypoxia-trained subjects.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Anatomy > Functional Anatomy 04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Anatomy
UniBE Contributor:	Vogt, Michael, Hoppeler, Hans-Heinrich, Flück, Martin
ISSN:	8750-7587
ISBN:	16540710
Publisher:	American Physiological Society
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:46
Last Modified:	05 Dec 2022 14:14
Publisher DOI:	10.1152/japplphysiol.00359.2005
PubMed ID:	16540710
Web of Science ID:	000236854500025
URI:	https://boris.unibe.ch/id/eprint/18941 (FactScience: 1212)