Recovery from Fatigue after Cycling Time Trials in Elite Endurance Athletes

Introduction We determined the recovery from neuromuscular fatigue in six professional (PRO) and seven moderately trained (MOD) cyclists after repeated cycling time trials of various intensities/durations. Method Participants performed two 1-min (1(min)TT) or two 10-min (10(min)TT) self-paced cycling time trials with 5 min of recovery in between. Central and peripheral fatigue were quantified via preexercise to postexercise (15-s through 15-min recovery) changes in voluntary activation (VA) and potentiated twitch force. VA was measured using the interpolated twitch technique, and potentiated twitch force was evoked by single (QT(single)) and paired (10-Hz (QT(10)) and 100-Hz (QT(100))) electrical stimulations of the femoral nerve. Results Mean power output was 32%-72% higher during all the time trials and decreased less (-10% vs -13%) from the first to second time trial in PRO compared with MOD (P < 0.05). Conversely, exercise-induced reduction in QT(single) and QT(10)/QT(100) was significantly lower in PRO after every time trial (P < 0.05). Recovery from fatigue from 15 s to 2 min for QT(single) and QT(10)/QT(100) was slower in PRO after every time trial (P < 0.05). In both groups, the reduction in QT(single) was lower after the 10(min)TTs compared with 1(min)TTs (P < 0.05). Conversely, VA decreased more after the 10(min)TTs compared with 1(min)TTs (P < 0.05). Conclusion Our findings showed that excitation-contraction coupling was preserved after exercise in PRO compared with MOD. This likely contributed to the improved performance during repeated cycling time trials of various intensity/duration in PRO, despite a slower rate of recovery in its early phase. Finally, the time course of recovery from neuromuscular fatigue in PRO was dependent on the effects of prolonged low-frequency force depression.

Automated summary

The study found that professional cyclists showed better performance and slower recovery from neuromuscular fatigue compared to moderately trained cyclists in repeated cycling time trials of various intensities/durations.