Introduction: In some endurance sports athletes complete several competitions within a short period of time, resulting in accumulated fatigue. It is unclear if fatigued athletes choose the same pacing pattern (PP) as when they are recovered.
Purpose: To analyze effects of fatigue on PP of cyclists during a 40 km time trial (TT).
Methods: 23 male cyclists (28.8 +/- 7.6 y) completed three 40 km TTs on a cycle ergometer. TTs were conducted before (TT1) and after (TT2) a 6-day training period. A third TT was carried out after 72 h of recovery (TT3). Training days consisted of 2 cycling sessions; mornings: 1 h at 95 % of lactate threshold (LT) or 3 x 5 x 30 s all-out sprint; afternoons: 3 h at 80 % IAT. 4 km split times (min) and rating of perceived exertion (RPE) was recorded during TTs.
Results: Performance decreased from TT1 to TT2 (65.7 +/- 3.5 vs. 66.7 +/- 3.3 min; P < 0.05) and increased from TT2 to TT3 (66.7 +/- 3.3 vs. 65.5 +/- 3.3 min; P < 0.01). PP showed a significant difference between TT1 and TT2 (P < 0.001) as well as between TT2 and TT3 (P< 0.01). PP in TT1 and TT3 showed no significant difference (P > 0.05). In TT1 and TT3 cyclists started faster in the first 4 km compared to TT2. RPE course showed no significant difference between TTs (P > 0.05).
Conclusions: Fatigue reversibly changes the PP of cyclists during a 40 km TT. Participants reduced their power output until premature exhaustion seemed very unlikely. This supports the assumption that pacing includes a combination of anticipation and feedback mechanisms.
(C) 2014 American College of Sports Medicine