Effect of Intensified Endurance Training on Pacing and Performance in 4000m Cycling Time-Trials

Studies examining pacing strategies during 4000m cycling time-trials (TTs) typically ensure participants are not pre-fatigued, however competitive cyclists often undertake TTs when already pre-fatigued. This study aimed to determine how TT pacing strategies and sprint characteristics of cyclists change during an intensified training period (mesocycle).

Thirteen cyclists, regularly competing in A and B grade cycling races and consistently training (>10 h·wk-1 for 4±1 years), completed a six-week training mesocycle. Participants undertook individually prescribed training, using training stress scores [(TSS, Training Peaks, Boulder, USA)], partitioned into a Baseline week, a Build week, two Loading weeks (designed to elicit an overreached state) and two Recovery weeks.

Laboratory based tests (15-s sprint and TT) and RESTQ-52 responses were repeatedly undertaken over the mesocycle. TT power output increased during Recovery compared to Baseline and Loading weeks (P=0.001) with >6 W increases in mean power output (MPO) detected for 400-m sections (10% bins) from 1200 m to 4000 m in Recovery weeks.

Decreases in peak heart rate (P<0.001) during Loading weeks and post-exercise blood lactate (P=0.005) during Loading week 2 and Recovery week 1 were detected. Compared to Baseline, 15-s sprint MPO declined during Loading and Recovery weeks (P<0.001). An interaction was observed between RESTQ-52 total stress score with 15-s sprint (P=0.003) and with TT MPO (P=0.04) indicating participants who experienced greater stress during Loading weeks exhibited reduced performance.

To conclude, intensified endurance training diminished sprint performance but improved 4,000 m TT performance, with a subtle change in MPO evident over the last 70% of TTs.

Wallet, A. M., Woods, A. L., Versey, N., Garvican-Lewis, L. A., Welvaert, M. & Thompson, K. G. (2018). Effect of intensified endurance training on pacing and performance in 4000m cycling time trials. International Journal of Sport Physiology and Performance, 13(6):735-741.