Multiple variables explain the variability in the decrement in V̇O(2max) during acute hypobaric hypoxia
Robergs, Robert A., Quintana, Roberto, Lee Parker, Daryl., & Frankel, Christopher Chaim (1998) Multiple variables explain the variability in the decrement in V̇O(2max) during acute hypobaric hypoxia. Medicine and Science in Sports and Exercise, 30(6), pp. 869-879.
- We used multiple regression analyses to determine the relationships between the decrement in sea level (SL, 760 Torr) V˙O2max during hypobaric hypoxia (HH) and variables that could alter or be related to the decrement in V˙O2max.
- HH conditions consisted of 682 Torr, 632 Torr, and 566 Torr, and the measured independent variables were SL-V˙O2max, SL lactate threshold (SL-LT), the change in hemoglobin saturation at V˙O2max between 760 and 566 Torr (ΔSaO2max), lean body mass (LBM), and gender. Male (N = 14) and female (N = 14) subjects of varied fitness, training status, and residential altitude (1,640-2,460 m) completed cycle ergometry tests of V˙O2max at each HH condition under randomized and single-blinded conditions.
- V˙O2max decreased significantly from 760 Torr after 682 Torr (∼915 m) (3.5 ± 0.9 to 3.4 ± 0.8 L·min−1, P = 0.0003). Across all HH conditions, the slope of the relative decrement in V˙O2max (%V˙O2max) during HH was −9.2%/100 mm Hg (−8.1%/1000 m) with an initial decrease from 100% estimated to occur below 705 Torr (610 m). Step-wise multiple regression revealed that SL-V˙O2max, SL-LT, ΔSaO2max, LBM, and gender each significantly combined to account for 89.03% of the variance in the decrement in V˙O2max (760-566 Torr) (P < 0.001).
- Individuals who have a combination of a large SL-V˙O2max, a small SL-LT (V˙O2, L·min−1), greater reductions in ΔSaO2max, a large LBM, and are male have the greatest decrement in V˙O2max during HH. The unique variance explanation afforded by SL-LT, LBM, and gender suggests that issues pertaining to oxygen diffusion within skeletal muscle may add to the explanation of between subjects variability in the decrement in V˙O2max during HH.
Impact and interest:
Citation counts are sourced monthly from and citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
|Item Type:||Journal Article|
|Keywords:||adult; article; clinical trial; controlled study; female; human; human experiment; hypobarism; hypoxemia; hypoxia; male; normal human; oxygen diffusion; oxygen saturation; oxygen transport; randomized controlled trial; sex difference; skeletal muscle, Adult; Altitude; Anoxia; Atmospheric Pressure; Biological Transport; Diffusion; Exercise; Female; Humans; Male; Muscle, Skeletal; Oxygen; Sex Factors|
|Divisions:||Current > QUT Faculties and Divisions > Faculty of Health
Current > Schools > School of Exercise & Nutrition Sciences
|Deposited On:||21 Jul 2016 03:30|
|Last Modified:||09 Aug 2016 03:33|
Repository Staff Only: item control page