Author(s): MORIN, F., BIEUZEN, F., SIMONELLI, G., VARESCO, G., Institution: INSTITUT NATIONAL DU SPORT DU QUÉBEC, Country: CANADA, Abstract-ID: 1607

INTRODUCTION:
Sleep is a key component for performance. The frequent travel required of elite athletes for competition negatively impacts sleep. Nevertheless, elite canadian speed skating athletes appear to adapt rapidly to long-haul travel [1]. More recently, research in this same population has identified sex as a key determinant of sleep during preseason [2]. This study aimed to determine (a) whether sex differences in sleep previously observed during the preseason persist during long-haul travel in the competitive season, and (b) whether sleep adaptation kinetics differ between men and women.
METHODS:
Secondary sex-based analyses were conducted using data from a a previously published longitudinal observational study in Canadian national team speed skaters (n=19; 11 women) traveling from Western Canada to Asia for World Cup competitions between 2017 and 2019 [1]. Sleep was assessed using wrist-worn actigraph MotionWatch 8 (CamNtech, Cambridge, UK) across different phases (baseline, travel day, training in Asia and competition days), with a particular focus on the time course of sleep adaptation from the arrival in Asia until the first competition (5 days). Countermovement jump height (CMJ) was assessed in a subsample (n = 8; 4 women) using a portable force plate (PS-2142, Pasco, Roseville, CA, USA).
RESULTS:
No phase x sex interaction was observed for total sleep time (p=0.90). Sleep duration baseline was similar across women (428±56 min) vs men (429±51 min, p=0.86). The previously reported increase in sleep duration (9±2 min·day⁻¹) during the training period in Asia was not influence by sex (day x sex interaction: p=0.61). Similar results were observed for sleep efficiency (85 ± 1%; p=0.30) and for all other sleep-related outcomes, with no sex effect (p>0.05). The only sex-related difference was found for neuromuscular performance. Men exhibited higher CMJ than women (+11 ± 4 cm, p = 0.04), with a significant day effect (+1.0 ± 0.3 cm·day⁻¹, p < 0.001) and no day x sex interaction (p = 0.44).
CONCLUSION:
Sex differences observed during the preseason may be attenuated during the competitive season, where training and competition schedules are highly standardized across athletes. Future studies should examine these effects within the same athletes across a single competitive year. Overall, men and women appear to adapt similarly to long-haul travel in terms of sleep and neuromuscular performance.

[1] Varesco et al., 2024; [2] Varesco et al., 2025