Measurement of a True [Formula: see text]O during a Ramp Incremental Test Is Not Confirmed by a Verification Phase.

The accuracy of an exhaustive ramp incremental (RI) test to determine maximal oxygen uptake ([Formula: see text]O) was recently questioned and the utilization of a verification phase proposed as a gold standard. This study compared the oxygen uptake ([Formula: see text]O) during a RI test to that obtained during a verification phase aimed to confirm attainment of [Formula: see text]O. Sixty-one healthy males [31 older (O) 65 ± 5 yrs; 30 younger (Y) 25 ± 4 yrs] performed a RI test (15-20 W/min for O and 25 W/min for Y). At the end of the RI test, a 5-min recovery period was followed by a verification phase of constant load cycling to fatigue at either 85% ( = 16) or 105% ( = 45) of the peak power output obtained from the RI test. The highest [Formula: see text]O after the RI test (39.8 ± 11.5 mL·kg·min) and the verification phase (40.1 ± 11.2 mL·kg·min) were not different ( = 0.33) and they were highly correlated ( = 0.99; < 0.01). This response was not affected by age or intensity of the verification phase. The Bland-Altman analysis revealed a very small absolute bias (-0.25 mL·kg·min, not different from 0) and a precision of ±1.56 mL·kg·min between measures. This study indicated that a verification phase does not highlight an under-estimation of [Formula: see text]O derived from a RI test, in a large and heterogeneous group of healthy younger and older men naïve to laboratory testing procedures. Moreover, only minor within-individual differences were observed between the maximal [Formula: see text]O elicited during the RI and the verification phase. Thus a verification phase does not add any validation of the determination of a [Formula: see text]O. Therefore, the recommendation that a verification phase should become a gold standard procedure, although initially appealing, is not supported by the experimental data.