Sex Differences in Performance Loss Above Critical Power in Professional Cyclists.

Area of Science:

• Sports Science
• Exercise Physiology
• Cycling Performance

Background:

• Sex differences in physiological responses to exercise are critical for optimizing athletic performance.
• Understanding performance loss above critical power is essential for elite cycling training and race tactics.
• Limited research exists on sex-specific fatigue accumulation in professional cyclists.

Purpose of the Study:

• To investigate sex-specific differences in performance loss above critical power in elite cyclists.
• To analyze how accumulated work levels and effort durations influence sex-based performance decay.
• To correlate physiological markers with observed performance differences.

Main Methods:

• Analysis of power output data from 16 female and 17 male WorldTour professional cyclists over one season.
• Quantification of performance loss using accumulated work above critical power (kJ kg^-1).
• Assessment of power decay across various effort durations (5s to 20 min).

Main Results:

• Men showed significantly less performance loss at 5 kJ kg^-1 accumulated work (16.58±10.44%) compared to women (29.58±29.35%).
• Women experienced greater power decay in 5-minute efforts from 1 kJ kg^-1 and in 10-20 minute efforts from 1-2 kJ kg^-1.
• Men possessed higher estimated maximum oxygen uptake and critical power, suggesting better aerobic capacity for sustained high-intensity efforts.

Conclusions:

• Elite male cyclists demonstrate superior fatigue resistance compared to elite females, particularly under conditions of high accumulated work and prolonged high-intensity exercise.
• Physiological factors, including higher aerobic capacity (VO2max) and critical power in men, likely underpin these observed sex differences in performance sustainability.
• Findings underscore the importance of sex-specific physiological assessments for developing individualized training and race strategies in professional cycling.