Women Upward-Sex Differences in Uphill Performance in Speed Climbing, Ski Mountaineering, Trail Running, Cross-Country Skiing, and Cycling.

Introduction: Women have generally lower body size and lean- to fat-mass ratio, lower maximal anaerobic power due to a lower muscle mass, and fewer fast-twitch fibers, although they can show higher resistance to fatigue or greater metabolic flexibility than men. These factors are well known and explain the sex differences in endurance sports such as distance running (10%-12%). Several of these factors-particularly the differences in body composition and skeletal-muscle characteristics-may directly impact vertical displacement and uphill performance. However, there is a lack of sex-difference reports in sports with uphill locomotion.

Methods: The sex differences in world-level endurance performance over 10 years (2013-2022) in 6 different sports with uphill displacement (speed climbing, vertical race in ski mountaineering, vertical kilometer in mountain running, cycling, cross-country skiing, and ultratrail running) were calculated.

Results: The sex differences are generally larger (18%-22%) than in endurance sports performed primarily on flat terrains. This may be due to the lower lean- to fat-mass ratio commonly reported in women. In shorter uphill events (eg, sport climbing, vertical kilometer, and short climb in cycling), the sex differences appear even more pronounced (28%-35%), potentially being explained by additional factors (eg, anaerobic capacity, muscle composition, and upper-body contribution).

Conclusion: This novel analysis over 10 years of elite endurance performance in different sports with uphill displacement shows that the sex differences are generally larger (18%-22%) than in endurance sports performed primarily on flat terrains.