A proposed test for determining physical working capacity at the oxygen consumption threshold (PWC_V̇O2)

The purpose of this study was 3-fold: (a) to determine if the mathematical model used to estimate the electromyographic fatigue threshold (EMG _FT) and physical working capacity at the heart rate threshold (PWC_HRT) could be applied to V̇_O2 measurements, (b) to propose a new fatigue threshold called the physical working capacity at the oxygen consumption threshold (PWC_V̇O2), and (c) to compare the power output at the PWC_V̇O2 to those of the EMG_FT, PWC_HRT, and ventilatory threshold (VT). Fifteen adult volunteers (mean age ± SD = 22 ± 2 years) performed a maximal cycle ergometer test to determine V̇O₂peak and VT as well as 4 8-minute submaximal work bouts for the determination of PWC_HRT, EMG _FT, and PWC_V̇O2- A 1-way repeated measures analysis of variance (ANOVA) with Tukey post hoc comparison indicated that PWC _HRT (84 ± 36) was significantly (p < 0.05) less than EMG_FT (126 ± 51), but there were no differences for PWC _V̇O2 (111 ± 44) and VT (111 ± 60) versus PWC _HRT or EMG_FT. The results of this study indicated that (a) the mathematical model used to determine the PWC_HRT and EMG _FT was applicable to the measurement of V̇O₂ and could be used to estimate the PWC_V̇O2 during cycle ergometry, (b) there was a difference in the mean power outputs that corresponded to the fatigue thresholds determined from EMG and heart rate measurements, and (c) the PWC_V̇O2 test may provide a useful submaximal technique for estimating the VT.