An integrated view of the determinants of maximum oxygen uptake.

This paper develops an analysis of the interaction between circulatory convective and tissue diffusive O2 transport that explains how VO2 max is set by the integrated response to each and every step in the O2 transport chain from atmosphere to mitochondria. We suggest that it is not useful to search for "the" rate limiting step determining VO2max; rather, all steps contribute. Beyond these basic concepts, the theory accounts for observations of VO2max at altitude, permits experimentally testable predictions of VO2max under a variety of conditions, explains the concept of critical O2 delivery below which VO2 cannot be maintained, and suggests an analysis to separate the contributions of central convective from peripheral diffusive adaptations to stimuli such as exercise training and chronic altitude exposure.