Sex differences in durability: A field-based study in professional cyclists.

Objectives: Durability is emerging as a key performance determinant in cycling, but scarce evidence exists on the durability of female cyclists, and particularly on whether there are sex differences. We therefore aimed to determine potential sex differences in durability.

Design: Observational field-based study.

Methods: Power output data from training and competitions were registered in female and male professional cyclists (n = 42 each) during 1-5 seasons. Participants' highest power output values achieved for different effort durations (10 s, 1 min, 5 min, and 20 min) (or 'record power profile') were determined under non-fatigued conditions (0 kJ/kg) and after varying levels of accumulated work (10, 20 and 30 kJ/kg).

Results: A significant reduction in the record power profile compared with non-fatigued conditions was observed after > 10 kJ/kg in both female and male cyclists (p < 0.001), with no significant impairment observed below this level of accumulated work (p > 0.05 for all). A similar relative decay (% decline compared with the fresh condition) was observed between sexes for 10-s efforts (p > 0.05). However, a significantly higher relative decay was observed in female cyclists after 20 kJ/kg for 1-min, 5-min, and 20-min efforts (4 %, 4 % and 2 %, respectively; p < 0.05), with these differences enlarging after 30 kJ/kg (8 %, 6 % and 7 %; p < 0.001).

Conclusions: Professional female cyclists show a greater relative decay in the record power profile after a given accumulated work compared to male cyclists, which might reflect a lower durability.