Absence of work efficiency differences during cycle ergometry exercise in Bolivian Aymara

Abstract

ABSTRACT. This study tested the hypothesis that Andean natives are adapted to high altitude (HA) via high work ef ficiency during exercise in hypoxia. A total of 186 young males and females were tested in Bo livia, comprising eight different subject groups. Groups were identified based on gender, an cestry (Aymara vs. European), altitude of birth (highlands vs. lowlands), and the altitude where tested (420, 3600, 3850 m). This design allows partitioning of ancestral (i.e., genetic) and devel opmental effects. To minimize measurement error, subjects were given two submaximal exer cise tests on a cycle ergometer (on separate days). Each test consisted of four 5-min work bouts (levels), each separated by a 5-min rest period. For all groups, the oxygen consumption (VO2)–work rate relationship was not different from the sea-level reference. Gross and net effi ciencies (GE and NE) were not different between groups at any work level, with the exception of European men born in the lowlands and acclimatized and tested at 3600 m. These men showed slightly lower VO2 at high work output, but this may be due to a nonsteady-state VO2 kinetic, rather than to an altered steady-state VO2–work rate relationship per se. There were no signifi cant group differences in delta efficiency (DE). In sum, these results provide no support for the hypothesis of energetic advantage during submaximal work in Andean HA natives. A review and analysis of the literature suggest that the same is true for HA natives in the Himalayas.