How important is V̇O2max when climbing Mt. Everest (8,849 m)?

Abstract

The maximal rate of oxygen uptake (V̇O2max) of humans declines with increasing altitude, but represents the upper limit of aerobic endurance performance at low and high altitude as well. Before Reinhold Messner and Peter Habeler climbed Mt. Everest first (1978) without supplemental oxygen, physiologists have doubted whether this would be possible due to insufficient V̇O2max remaining when approaching the summit (8849 m). Subsequently, several studies evaluated the decline in the V̇O2max levels at real and simulated extreme altitudes. However, the potential influence of the preexisting individual sea level V̇O2max remained largely unconsidered. Based on available studies and case observations, here we discuss the observed and expected decline of V̇O2max up to 8849 m dependent on the individual sea level V̇O2max. It is concluded that a high sea level V̇O2max and an only moderate decline of arterial oxygen saturation and associated V̇O2max with increasing altitude, due to appropriate acclimatization and ascent strategies, enable certain mountaineers to climb 8,000er summits and even the Everest without supplemental oxygen.