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

Purpose: We investigated the influence of pacing strategy on the work completed above critical power (CP) before exhaustion (W->CP) and the peak VO2 attained during high-intensity cycling. Methods: After the determination of VO2max 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). Results: The VO2max determined from INC was 4.24 +/- 0.69 L.min(-1), and the CP and the W' estimated from AOT were 260 +/- 60W 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 VO2 during SPT was not significantly different from peak VO2 during CWR (4.20 +/- 0.77 and 4.14 +/- 0.75 L.min(-1), respectively), and these values were similar to the VO2max determined from INC and the peak VO2 during AOT (4.10 +/- 0.79 L.min(-1)). Conclusion: Exhaustion during high-intensity exercise coincides with the achievement of the same peak VO2 (VO2max) 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.