Influence of Chronotype on Cycling Performance in Simulated 20-km Time Trials-A Pilot Study

The chronotype (CT) refers to an individual's diurnal preference towards morningness (M) or eveningness (E). The aim of this study was to determine the influence of chronotype on 20-km cycling performance throughout the day. Seventy-six competitive male cyclists and triathletes completed the Morningness-Eveningness Questionnaire to determine chronotype. Only participants categorised as 'definite' M- (n = 10) and E-types (n = 7) were included in the study. In a randomised order and separated by 2-7 days, participants performed four self-paced 20-km cycling time trials at four different times of the day (06:00 h, 12:00 h, 18:00 h, 22:00 h). Mental readiness was assessed before each trial. Performance across all participants was significantly better in the evening compared to the morning (change: 2.1% ± 3.8%; p = 0.008). Related to individual's mean performance E-types performed significantly better in the evening compared to the morning (p = 0.02). Specifically, athletes were 40 s faster at 18:00 h compared to 06:00 h. Mental readiness in E-type athletes was significantly lower at 06:00 h compared to all other times (p < 0.04). The present study indicates that E-type athletes perform better later in the day. This might be important for the scheduling of training times and the preparation for competition, especially in the morning.