Effects of Pacing Strategy on Work Done above Critical Power during High-Intensity Exercise

Abstract

We investigated the influence of pacing strategy on the work completed above critical power (CP) before exhaustion (W>CP) and the peak V˙O2 attained during high-intensity cycling. After the determination of VO(2max) from a ramp incremental cycling (INC) test and the estimation of the parameters of the power-duration relationship for high-intensity exercise (i.e., CP and W') from a 3-min all-out cycling test (AOT), eight male subjects completed a cycle test to exhaustion at a severe-intensity constant work rate (CWR) estimated to result in exhaustion in 3 min and a self-paced 3-min cycling time trial (SPT). The VO(2max) determined from INC was 4.24 ± 0.69 L · min(-1), and the CP and the W' estimated from AOT were 260 ± 60 W and 16.5 ± 4.0 kJ, respectively. W>CP during SPT was not significantly different from W>CP during CWR (15.3 ± 5.6 and 16.6 ± 7.4 kJ, respectively), and these values were also similar to W(>CP) during INC (16.4 ± 4.0 kJ) and W' estimated from AOT. The peak VO(2) during SPT was not significantly different from peak VO(2) during CWR (4.20 ± 0.77 and 4.14 ± 0.75 L · min(-1), respectively), and these values were similar to the VO(2max) determined from INC and the peak VO(2) during AOT (4.10 ± 0.79 L · min(-1)). Exhaustion during high-intensity exercise coincides with the achievement of the same peak VO2 (VO(2max)) and the completion of the same W>CP, irrespective of the work rate forcing function (INC or CWR) or pacing strategy (enforced pace or self-paced). These findings indicate that exhaustion during high-intensity exercise is based on highly predictable physiological processes, which are unaffected when pacing strategy is self-selected.