Sex differences in classical and skating cross-country skiing time-trial competitions

Abstract Purpose To compare differences in speed, sub-technique selection, and kinematics between male and female cross-country skiers during 10-km time-trial competitions. Methods Elite- to world-class skiers performed FIS-regulated 3 × 3.3-km classical (12 women, 22 men) and skating (15 women, 32 men) competitions. A combined GNSS and IMU unit were used to determine speed, sub-technique selection, and kinematics. Results Average speeds for men were 12% higher than for women in both styles (both P < .001), with no differences between laps, indicating similar lap-to-lap pacing. Men demonstrated 18, 10, and 5% higher speeds in uphill, flat, and downhill terrains, respectively, for classical and 17, 6, and 5% for skating (all P < .05). Further, men spent 3%-point less of their relative time in uphill and correspondingly more time in flat and downhill terrain (all P < .001). In classical, men spent ⁓10%-point more of their total time in double poling and corresponding ⁓9%-point less time in diagonal than women (both P < .001). In skating, men spent ⁓9%-point more of their total time in the Gear-3 and ⁓12%-point less time in the Gear-2 sub-technique (all P < .001). This was accompanied by ⁓7–19% longer cycle lengths in both styles for men compared to women (all P < .05). Conclusion Average performance differences between sexes in classical and skating cross-country skiing time trials are around 12% but highly terrain dependent, with the largest sex differences in uphill terrain. These distinct competitive demands between sexes, including more time spent in uphill terrain and more use of “low-speed gears” in women, highlight a potential need for sex-specific training strategies.