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Live high: train low increases muscle buffer capacity and submaximal cycling efficiency

Gore, Christopher J and Hahn, Allan G and Aughey, Robert J and Martin, David T and Ashenden, M. J and Clark, Sally A and Garnham, Andrew P and Roberts, A. D and Slater, G. J and McKenna, Michael J (2001) Live high: train low increases muscle buffer capacity and submaximal cycling efficiency. Acta Physiological Scandinavica, 173 (3). pp. 275-286. ISSN 00016772

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Abstract

This study investigated whether hypoxic exposure increased muscle buffer capacity (βm) and mechanical efficiency during exercise in male athletes. A control (CON, n=7) and a live high:train low group (LHTL, n=6) trained at near sea level (600 m), with the LHTL group sleeping for 23 nights in simulated moderate altitude (3000 m). Whole body oxygen consumption (V˙O2) was measured under normoxia before, during and after 23 nights of sleeping in hypoxia, during cycle ergometry comprising 4×4-min submaximal stages, 2-min at 5.6 ± 0.4 W kg–1, and 2-min 'all-out' to determine total work and V˙O2peak. A vastus lateralis muscle biopsy was taken at rest and after a standardized 2-min 5.6 ± 0.4 W kg–1 bout, before and after LHTL, and analysed for βm and metabolites. After LHTL, βm was increased (18%, P < 0.05). Although work was maintained, V˙O2peak fell after LHTL (7%, P < 0.05). Submaximal V˙O2 was reduced (4.4%, P < 0.05) and efficiency improved (0.8%, P < 0.05) after LHTL probably because of a shift in fuel utilization. This is the first study to show that hypoxic exposure, per se, increases muscle buffer capacity. Further, reduced V˙O2 during normoxic exercise after LHTL suggests that improved exercise efficiency is a fundamental adaptation to LHTL.

Item Type: Article
Uncontrolled Keywords: altitude training, cycling effeciency, hypoxia, muscle buffering
Subjects: RFCD Classification > 320000 Medical and Health Sciences
RFCD Classification > 220000 Social Sciences, Humanities and Arts-General
Faculty/School/Research Centre/Department > School of Sport and Exercise Science
Depositing User: Ms Phung T Tran
Date Deposited: 17 Jun 2007 14:13
Last Modified: 30 Mar 2015 03:14
URI: http://vuir.vu.edu.au/id/eprint/989
DOI: 10.1046/j.1365-201X.2001.00906.x
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Citations in Scopus: 112 - View on Scopus

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