Methods to Estimate V˙O2max upon Acute Hypoxia Exposure

Abstract

These data provide a robust quantitative framework for the curvilinear and interacting effects of altitude and baseline V˙O2max in determining an individual's effective V˙O2max at altitude. This predictive model is useful for a priori power calculations, design of future experimental studies, and prediction of aerobic capacity declines in applied settings.

Prediction of Critical Power and W′ in Hypoxia: Application to Work-Balance Modelling

“…Consistent with data on the dose-response effect of hypoxia on $\dot{\text{V}}$O 2max (Bassett et al, 1999; MacInnis et al, 2015), we observed a curvilinear decrease in CP. Secondly, the effect of hypoxia on W′ appears to display threshold type characteristics since there were no significant changes at lower altitudes, whereas a decrease occurred at the highest altitude only (4,250 m).…”

“…Previous studies have quantified the decrease in $\dot{\text{V}}$O 2max that occurs at altitude (Bassett et al, 1999; Wehrlin and Hallén, 2006; Clark et al, 2007; MacInnis et al, 2015), however this is the first to examine the effect of altitude on CP and W′. Consistent with data on the dose-response effect of hypoxia on $\dot{\text{V}}$O 2max (Bassett et al, 1999; MacInnis et al, 2015), we observed a curvilinear decrease in CP.…”

“…With increasing altitude, $\dot{\text{V}}$O 2max has been shown to decrease linearly (Wehrlin and Hallén, 2006; Clark et al, 2007), or curvilinearly (Bassett et al, 1999; MacInnis et al, 2015). The curvilinear decrease in CP observed in this study (see Figures 1A,C) was similar to that for $\dot{\text{V}}$O 2max reported by Bassett et al (1999).…”

“…Therefore, CP must either be tested in hypoxia, or estimated from measurements in normoxia. Various studies have examined the effect of increasing altitude on $\dot{\text{V}}$O 2max reporting either a linear decrease (Wehrlin and Hallén, 2006; Clark et al, 2007), a curvilinear decrease (Péronnet et al, 1991; Bassett et al, 1999), or a curvilinear interaction between altitude and sea level $\dot{\text{V}}$O 2max (MacInnis et al, 2015). To our knowledge, no studies have examined the dose-response effect of increasing altitude on CP and W′.…”

VESTPD as a measure of ventilatory acclimatization to hypobaric hypoxia

“…However, submaximal exercise endurance is clearly increased (22), as is the sense of well being and reduction of altitude illness. A recent meta-analysis of 80 studies, where altitude exposure was limited to 24 h, demonstrated that the decline in VO 2 max with altitude was greater for subjects with higher aerobic capacity (21). Their model predicts a 25% reduction from 1,600 to 4,350 m for subjects in this study, well above 15.5%.…”