Titre
Muscle structure and performance capacity of Himalayan Sherpas.
Type
article
Institution
Externe
Périodique
Auteur(s)
Kayser, B.
Auteure/Auteur
Hoppeler, H.
Auteure/Auteur
Claassen, H.
Auteure/Auteur
Cerretelli, P.
Auteure/Auteur
Liens vers les personnes
ISSN
8750-7587
Statut éditorial
Publié
Date de publication
1991
Volume
70
Numéro
5
Première page
1938
Dernière page/numéro d’article
1942
Langue
anglais
Résumé
The ultrastructure of the vastus lateralis muscle of Sherpas from Nepal [5 males; age 28 +/- 2.8 (SD) yr, indirect maximal O2 consumption 48.5 +/- 5.4 ml.kg(-1).min(-1)] was assessed and compared with those of sedentary lowlanders and of Caucasian climbers before and after high-altitude exposure. The mean cross-sectional area of the fibers was 3,186 +/- 521 microns2, i.e., similar to those of Caucasian elite high-altitude climbers (3,108 +/- 303 microns2) and a group of climbers after a 6- to 8-wk sojourn at 5,000-8,600 m (3,360 +/- 580 microns2) but significantly (P less than 0.05) smaller than that of unacclimatized climbers (4,170 +/- 710 microns2) and slightly, although not significantly, lower than that of sedentary lowlanders (3,640 +/- 260 microns2). The number of capillaries per square millimeter of muscle cross section was 467 +/- 22, not significantly smaller than those of climbers on return from a Himalayan expedition (538 +/- 89) and elite high-altitude climbers (542 +/- 127) but significantly (P less than 0.05) greater than that of sedentary lowlanders (387 +/- 25). The volume density of mitochondria was 3.96 +/- 0.54%, significantly (P less than 0.05) less than the values found for any other investigated group, including sedentary subjects at sea level (4.74 +/- 0.30%). It is concluded that Sherpas, like acclimatized Caucasian climbers, are characterized by 1) facilitated convective and diffusive muscle O2 flow conditions and 2) a higher maximal O2 consumption-to-mitochondrial volume ratio than lowlanders despite a reduced mitochondrial volume density.
PID Serval
serval:BIB_D628D06B54BC
PMID
Date de création
2013-09-19T09:33:54.980Z
Date de création dans IRIS
2025-05-20T23:25:18Z