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Whole body and regional body composition changes following 10-day hypoxic
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confinement and unloading/inactivity
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Tadej Debevec1, Adam C. McDonnell1,2, Ian A. Macdonald3, Ola Eiken4 Igor B.
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Mekjavic1
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Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
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Jozef Stefan International Postgraduate School, Jamova 39, Ljubljana, Slovenia 3
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MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research,
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University of Nottingham Medical School, School of Life Sciences, Queen's Medical
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Centre, Nottingham, NG7 2UH, United Kingdom
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Department of Environmental Physiology, School of Technology and Health, KTH Royal Institute of Technology, Berzelius v. 13, Stockholm, Sweden
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Corresponding author:
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Tadej Debevec
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Department of Automation, Biocybernetics and Robotics
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Jozef Stefan Institute
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Jamova 39, SI-1000, Ljubljana, Slovenia
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Phone:
00386 (1) 4773 777
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Fax:
00386 (1) 4773 154
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E-mail:
[email protected]
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Appl. Physiol. Nutr. Metab. Downloaded from www.nrcresearchpress.com by UNIV OF SOUTHERN MAINE on 10/24/13 For personal use only. This Just-IN manuscript is the accepted manuscript prior to copy editing and page composition. It may differ from the final official version of record.
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Abstract
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Future planetary habitats will expose inhabitants to both reduced gravity and hypoxia.
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This study investigated the effects of short-term unloading and normobaric hypoxia
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on whole body and regional body composition (BC). Eleven healthy, recreationally
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active, male participants with a mean(SD) age of 24(2) years and body mass index of
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22.4(3.2) kg⋅m2 completed three 10-day campaigns in a randomised, cross-over
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designed protocol: i) Hypoxic ambulatory confinement (HAMB; FIO2=0.147(0.008);
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PIO2=93.8(0.9)
mmHg),
ii)
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PIO2=93.8(0.9)
mmHg)
and
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PIO2=133.5(0.7) mmHg). Nutritional requirements were individually pre-calculated
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and the actual intake was monitored throughout the study protocol. Body mass, whole
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body and regional BC were assessed before and after the campaigns using dual-
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energy X-ray absorptiometry (DXA). The calculated daily-targeted energy intake
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values were 2071(170) kcal for HBR and NBR and 2417(200) kcal for HAMB. In
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both HBR and NBR campaigns the actual energy intake was within the targeted level
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whereas in the HAMB the intake was lower than targeted (- 8% p
