Commentaries on Viewpoint: V̇ o 2peak is an acceptable estimate of cardiorespiratory fitness but not V̇ o 2max
Résumé
to the editor: We can define V̇o2max as the highest oxygen delivered and utilized during exercise, and, if we increase the exercise intensity, the oxygen uptake will not increase. This assumption came from an original study of Hill and Lupton (2); they applied on different days higher intensities during a constant-work exercise. The authors observed that, above certain intensity, the O2 uptake does not increase. Because of the nature of the constant-work exercise, they observed a plateau phenomenon. Since then, plateau phenomenon has been the main “true” V̇o2max attainment criterion. If the plateau is not present, we consider it as V̇o2peak. However, the plateau is neither evident for ramp nor step protocol (5). The plateau appearance is dependent on data manipulation (4), subjects’ fitness, motivation, perceived exertion, and so on (3). Therefore, the plateau does not appear to be a natural physiological response in the face of the incremental exercise testing, and a plateau phenomenon is a wrong interpretation of Hill and Lupton study. As the maximum intensity achieved during incremental testing is dependent on, a priori, motivation (3), we must do the V̇o2max confirmation, independently of the plateau appearance, satisfying the main criterion “The O2 uptake does not increase irrespective of intensity increment.” In my view, the V̇o2peak is not a valid physiological index, and the terminology used in the Green and Askew (1) Viewpoint must be withdrawn from the scientific literature. The confirmation test is the best choice for cardiorespiratory assessments.