A standard method for the determination of maximal aerobic power from breath-by-breath VO2 data obtained during a continuous ramp test on a bicycle ergometer

There is no standard method for identifying a plateau in VO2 or determining VO2 peak where no plateau occurs. The purpose of the present investigation was to determine the optimal sample interval duration for VO2 data collected during incremental exercise tests on a bicycle ergometer and to define a plateau criterion that is applicable to a range of ramp rates. A statistical analysis was performed on VO2 data collected from 20 subjects who performed an incremental ramp test. Breath by breath data were analysed to determine the variance of VO2 which was used to calculate the minimum sample interval duration and a confidence interval which is used to identify a plateau in VO2 data. Results indicate that the accurate determination of VO2 to within a 5% error requires a minimum sample interval duration of 20 s. Further analysis indicates that a plateau may be defined as an increase in VO2 of less than 8.0 mL/min/Watt on the two highest successive 20 s sample intervals. The present plateau criterion is applicable to a range of test protocols for bicycle ergometry and is more selective than previous criteria. It is suggested that where no plateau occurs, the highest value in any (20 s) sample interval is chosen as labelled as VO2 peak.