Therefore, the V̇O2 kinetics of the population being assessed should be taken into account when planning or analysing the verification phase duration [11, 54].
In addition, exercise mode should also be observed because subjects exercising on a cycle ergometer would be more susceptible to local muscle fatigue compared to treadmill running which, in turn, could lead to a shorter verification phase duration on the first of these (i.e. cycle ergometer).
To increase the complexity of the network modeling for rigorous verification, the duration of the time series and time points were approximately 1.5 times of the default settings (changing from 21 to 31 time points).
Accordingly, both supramaximal and submaximal protocols appear to be suitable as long as the incremental test design is taken in consideration, while verification phase durations between 2 and 3 min should already be adequate for most, but not all, subjects.
➢ Both supramaximal and submaximal protocols appear to be suitable for measuring maximal oxygen consumption (V̇O2max), while verification phase durations between 2 and 3 min should already be adequate to confirm V̇O2max for most, but not all, subjects.
Another important aspect that can interfere with the result of the verification phase is its duration or, more precisely, the time to exhaustion during the phase.
The RSR2015 database, designed to evaluate text-dependent speaker verification systems under different durations and lexical constraints has been collected and released by the Human Language Technology (HLT) department at Institute for Infocomm Research (I2R) in Singapore.
The results of the second experiment on utterance verification indicate that combining duration-related features with a likelihood ratio (LR) yield an equal error rate (EER) of 10.3%, which is significantly better than the EER for the other measures in isolation.
Sawyer et al. [53] reported 1.91 min in sedentary obese and found no relationship between the duration of the verification phase and the difference between incremental test and verification phase V̇O2max.
This means that the duration of the verification phase should be sufficient to allow V̇O2max to be reached or evoked.
