Submaximal Verification Test to Exhaustion Confirms Maximal Oxygen Uptake: Roles of Anaerobic Performance and Respiratory Muscle Strength

<b>Background</b>: The incremental exercise test is commonly used to measure maximal oxygen uptake (VO₂max), but an additional verification test is often recommended as the "gold standard" to confirm the true VO₂max. Therefore, the aim of this study was to compare the peak oxygen uptake (VO₂peak) obtained in the ramp incremental exercise test and that in the verification test performed on different days at submaximal intensity. Additionally, we examined the roles of anaerobic performance and respiratory muscle strength. <b>Methods</b>: Sixteen physically active men participated in the study, with an average age of 22.7 ± 2.4 (years), height of 178.0 ± 7.4 (cm), and weight of 77.4 ± 7.3 (kg). They performed the three following tests on a cycle ergometer: the Wingate Anaerobic Test (WAnT), the ramp incremental exercise test (IET_RAMP), and the verification test performed at an intensity of 85% (VER₈₅) maximal power, which was obtained during the IET_RAMP. <b>Results</b>: No significant difference was observed in the peak oxygen uptake between the IET_RAMP and VER₈₅ (<i>p</i> = 0.51). The coefficient of variation was 3.1% and the Bland-Altman analysis showed a high agreement. We found significant correlations between the total work performed in the IET_RAMP, the anaerobic peak power (r = 0.52, <i>p</i> ≤ 0.05), and the total work obtained in the WAnT (r = 0.67, <i>p</i> ≤ 0.01). There were no significant differences in post-exercise changes in the strength of the inspiratory and expiratory muscles after the IET_RAMP and the VER₈₅. <b>Conclusions</b>: The submaximal intensity verification test performed on different days provided reliable values that confirmed the real VO₂max, which was not limited by respiratory muscle fatigue. This verification test may be suggested for participants with a lower anaerobic mechanical performance.