Measurement of a True (V)OverdotO2max 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 ((V)OverdotO(2max)) was recently questioned and the utilization of a verification phase proposed as a gold standard. This study compared the oxygen uptake ((V)OverdotO(2max)) during a RI test to that obtained during a verification phase aimed to confirm attainment of (V)OverdotO(2max). Sixty-one healthy males [31 older (0) 65 +/- 5 yrs; 30 younger (Y) 25 +/- 4 yrs] performed a RI test (15-20 W/min for 0 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% (n = 16) or 105% (n = 45) of the peak power output obtained from the RI test. The highest (V)OverdotO(2max) after the RI test (39.8 +/- 11.5 mL.kg(-1).min(-1)) and the verification phase (40.1 +/- 11.2 mL.kg(-1).min(-1)) were not different (p = 0.33) and they were highly correlated (r = 0.99; p < 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(-1).min(-1), not different from 0) and a precision of +/- 1.56 mL.kg(-1).min(-1) between measures. This study indicated that a verification phase does not highlight an under-estimation of (V)OverdotO(2max) derived from a RI test, in a large and heterogeneous group of healthy younger and older men naive to laboratory testing procedures. Moreover, only minor within-individual differences were observed between the maximal (V)OverdotO(2max) elicited during the RI and the verification phase. Thus a verification phase does not add any validation of the determination of a (V)OverdotO(2max). Therefore, the recommendation that a verification phase should become a gold standard procedure, although initially appealing, is not supported by the experimental data.