Sex Differences in Pacing Profile and Reliability in a 4-km Cycling Time Trial

BACKGROUND: Sex differences in pacing profile and day-to-day variability have been underexplored. Therefore, this study investigated potential sex differences in pacing profile, risk-taking behavior, and pacing reliability during a 4-km cycling time trial. HYPOTHESIS: Men and women present similar pacing and assume similar risk of premature trial interruption during a 4-km cycling time trial. In addition, it was hypothesized that men and women might present comparable performance and pacing reliability. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 4. METHODS: A total of 32 cyclists (16 men and 16 women) performed 2 4-km cycling time trials on separate days. Power output and ratings of perceived exertion were recorded during the trials. To quantify the risk of premature time-trial interruption, the hazard score was calculated as the product of the rating of perceived exertion and the remaining distance. RESULTS: > 0.05). However, the day-to-day coefficient of variation for power output distribution ranged from 3.5% to 7.2% in women and from 1.9% to 6.3% in men, indicating slightly greater day-to-day variability in the pacing profile for women. CONCLUSION: Men and women exhibit similar pacing profiles, risk-taking behavior, and endurance performance reliability during a 4-km cycling time trial. However, women seem to demonstrate greater day-to-day pacing profile variability than men. CLINICAL RELEVANCE: The present findings provide insights that enable more accurate monitoring and prescription of training protocols in female cyclists.