The Oxygen Uptake Plateau—A Critical Review of the Frequently Misunderstood Phenomenon
AbstractA flattening of the oxygen uptake–work rate relationship at severe exercise indicates the achievement of maximum oxygen uptake $$\left({\text{VO}}_{2\max } \right)$$ VO 2 max . Unfortunately, a distinct plateau $$\left( {{{\text{VO}}}_{2} {\text{pl}}} \right)$$ VO 2 pl at $${{\text{VO}}}_{2\max }$$ VO 2 max is not found in all participants. The aim of this investigation was to critically review the influence of research methods and physiological factors on the $${{\text{VO}}}_{2} {\text{pl}}$$ VO 2 pl incidence. It is shown that many studies used inappropriate definitions or methodical approaches to check for the occurrence of a $${{\text{VO}}}_{2} {\text{pl}}$$ VO 2 pl . In contrast to the widespread assumptions it is unclear whether there is higher $${{\text{VO}}}_{2} {\text{pl}}$$ VO 2 pl incidence in (uphill) running compared to cycling exercise or in discontinuous compared to continuous incremental exercise tests. Furthermore, most studies that evaluated the validity of supramaximal verification phases, reported verification bout durations, which are too short to ensure that $${{\text{VO}}}_{2\max }$$ VO 2 max have been achieved by all participants. As a result, there is little evidence for a higher $${{\text{VO}}}_{2} {\text{pl}}$$ VO 2 pl incidence and a corresponding advantage for the diagnoses of $${{\text{VO}}}_{2\max }$$ VO 2 max when incremental tests are supplemented by supramaximal verification bouts. Preliminary evidence suggests that the occurrence of a $${{\text{VO}}}_{2} {\text{pl}}$$ VO 2 pl in continuous incremental tests is determined by physiological factors like anaerobic capacity, $${{\text{VO}}}_{2}$$ VO 2 -kinetics and accumulation of metabolites in the submaximal intensity domain. Subsequent studies should take more attention to the use of valid $${{\text{VO}}}_{2} {\text{pl}}$$ VO 2 pl definitions, which require a cut-off at ~ 50% of the submaximal $${{\text{VO}}}_{2}$$ VO 2 increase and rather large sampling intervals. Furthermore, if verification bouts are used to verify the achievement of $${{\text{VO}}}_{{2{\text{peak}}}}$$ VO 2 peak /$${{\text{VO}}}_{2\max }$$ VO 2 max , it should be ensured that they can be sustained for sufficient durations.