Influence of feedback and prior experience on pacing during a 4-km cycle time trial

To determine the importance of distance knowledge, distance feedback, and prior experience on the setting of a pacing strategy.

Eighteen well-trained male cyclists were randomly assigned to a control (CON) group or an experimental (EXP) group and performed four consecutive 4-km time trials (TT), separated by a 17-min recovery. The CON group received prior knowledge of distance to be cycled and received distance feedback throughout each TT; the EXP group received neither but knew that each TT was of the same distance.

The EXP group was significantly slower than the CON group to complete TT1 (367.4 +/- 21 vs 409.4 +/- 45.5 s, P < 0.001). Differences between groups in completion time reduced over successive TT (CON TT4 = 373.9 +/- 20 s vs EXP TT4 = 373.8 +/- 14.4 s), shown by a significant linear contrast (F1,16 = 12.39, P < 0.0005). Mean speed and power output also showed significantly reduced differences between groups over successive TT (P < 0.0005). However, peak power output showed no such convergence between groups over TT. End blood lactate was significantly different between groups in TT1, but differences between groups converged with successive TT.

The progressively improving completion times in the EXP group show that distance feedback is not essential in developing an appropriate pacing strategy. Prior experience of an unknown distance appears to allow the creation of an internal, relative distance that is used to establish a pacing strategy.