Schaun GZ

Sports Med Open. 2017 Dec 8;3(1):44. doi: 10.1186/s40798-017-0112-1.

Commonly performed during an incremental test to exhaustion, maximal oxygen
uptake (V̇O2max) assessment has become a recurring practice in clinical and
experimental settings. To validate the test, several criteria were proposed. In
this context, the plateau in oxygen uptake (V̇O2) is inconsistent in its
frequency, reducing its usefulness as a robust method to determine “true”
V̇O2max. Moreover, secondary criteria previously suggested, such as expiratory
exchange ratios or percentages of maximal heart rate, are highly dependent on
protocol design and often are achieved at V̇O2 percentages well below V̇O2max.
Thus, an alternative method termed verification phase was proposed. Currently, it
is clear that the verification phase can be a practical and sensitive method to
confirm V̇O2max; however, procedures to conduct it are not standardized across
the literature and no previous research tried to summarize how it has been
employed. Therefore, in this review the knowledge on the verification phase was
updated, while suggestions on how it can be performed (e.g. intensity, duration,
recovery) were provided according to population and protocol design. Future
studies should focus to identify a verification protocol feasible for different
populations and to compare square-wave and multistage verification phases.
Additionally, studies assessing verification phases in different patient
populations are still warranted.