Effect of workbout duration on the physical working capacity at fatigue threshold (PWCFT) test.

The purpose of this study was twofold: (1) to determine the effect of increasing the duration of the workbout at each power output during the physical working capacity at fatigue threshold (PWCFT) test from 2 to 3 or 4 min, and (2) to examine the time to exhaustion during continuous workbouts at the PWCFT. Twelve adult males (means +/- SD = 22.4 +/- 3.0 years) volunteered to perform three PWCFT tests using workbout durations of 2, 3, and 4 min. Following the determination of the PWCFT values, nine of the subjects performed continuous workbouts at PWCFT2 and PWCFT4 for as long as possible. The mean PWCFT value using 4-min workbouts (PWCFT4 = 168.8 +/- 45.1 W) was significantly less (p < 0.05, 19.1%) than that using 2-min workbouts (PWCFT2 = 208.9 +/- 59.0 W). However, only two subjects were able to complete 60 min at PWCFT4 and none of the subjects were able to complete 60 min at PWCFT2. Therefore, although increasing the duration of the workbout at each power output resulted in a lower PWCFT4, these findings do not support a recommendation for a change in the PWCFT test protocol.