ECSS Paris 2023: CP-AP23
INTRODUCTION: Solo offshore racing imposes extreme constraints. Prolonged sleep restriction is considered inevitable, compromising skippers’ performance and safety. Moreover, sleep management strategies are rare and onboard sleep environments are suboptimal. This case study measured the 2024 Vendée Globe winner’s sleep, examined the influence of contextual factors on sleep, and investigated the perceived relationship between sleep and performance. METHODS: Sleep was measured onshore using actigraphy and at sea using dedicated onboard sleep-monitoring tool. Each sleep episode was manually initiated and terminated by the skipper via a computer, followed by a self-rated sleep quality score. Wind force, wind angle, boat speed and air temperature were collected. A semi-structured interview was conducted post-race. RESULTS: Over 64 days, 19 h, 22 min and 49 s, the skipper adopted a polyphasic sleep pattern (41.3 ± 10.5 episodes/24 h). Average time in bed (8h22 ± 2h20) and total sleep time (6h30 ± 1h05) were comparable to onshore values (8:03 ± 0:31; 6:23 ± 0:25). Forty-nine percent of episodes were rated moderate-to-good. Nighttime episodes (21h–6h) were overrepresented, suggesting circadian rhythm preservation. Interview data identified four functional-impairment moments and two peak-functioning periods, aligned respectively with decreasing and increasing 24-h rolling sleep. Wind angle modestly influenced sleep duration. CONCLUSION: Despite extreme constraints of solo ocean racing, optimized sleep management allowed the skipper to maintain sleep quantity and quality close to onshore. Fluctuations in 24-h rolling sleep appeared correlated to operational functioning. Findings suggest that sleep management strategies can improve performance and safety in solo offshore racing.
Read CV Arthur Le DeuffECSS Paris 2023: CP-AP23
INTRODUCTION: Menstrual dysfunction is more prevalent in elite female athletes compared to the general population. Sleep is critical to athletic performance, yet the impact of menstrual dysfunction on sleep remains poorly understood. This study investigated sleep quantity and quality by, comparing those classified with menstrual dysfunction to healthy natural menstruating female athletes. METHODS: Elite female athletes (n=71; age 23 ± 6.5 years) classified as Tier 3 (Highly Trained), Tier 4 Elite/International) and Tier 5 (World Class) athletes were monitored for two cycles, or equivalent timeframes for Hormonal Contraceptive (HC) users. The Pittsburgh Sleep Quality Index (PSQI) evaluated initial sleep quality. Objective sleep data was collected throughout the observation period using the Oura Ring Gen3. A sleep diary and menstrual symptom survey was completed in the morning by athletes daily. Venous blood samples were collected at Phases 1, 3, and 4 in naturally menstruating participants to capture distinct hormonal profiles and confirm cycle phases, with corresponding timepoints chosen for HC users. RESULTS: Following two monitored menstrual cycles, athletes were categorised into five groups: HC users, naturally menstruating – ovulation determined (NM-Ov), naturally menstruating – without determined ovulation (NM-Anov), abnormal uterine bleeding (AUB), and ovarian dysfunction (OD). Although 66% of participants were classified as “poor sleepers” based on the initial PSQI, objective measures (Oura Ring) of total sleep duration indicated that all groups obtained between 7.5 to 7.7 hours. Sleep efficiency was also not different between cohorts, ranging from 89.3% to 90.5%. However, significant intra- and inter-individual variation was observed in deep sleep duration (HC: 82.7 min; NM-Ov: 94.7 min; NM-Anov: 81.2 min; AUB: 97.3 min; OD: 88.8 min). Notably, participants with NM-Anov and AUB demonstrated significant declines in deep sleep duration across cycle days, whereas no systematic cycle-related changes were observed in the NM-Ov or OD groups. CONCLUSION: These results highlight the discrepancies between subjective and objective sleep measures in female athletes. Our novel findings suggest that while total sleep duration remains stable across various menstrual statuses, specific menstrual dysfunctions may lead to altered sleep architecture. The substantial individual variation in deep sleep duration highlights that the relationship between menstrual health and sleep is highly individualised. Fluctuations in deep sleep duration may have considerable physiological consequences for elite athletes, as this stage of sleep is critical for physical recovery. Consequently, the impact of menstrual dysfunction on athlete’s sleep warrants individualised assessment to identify athletes experiencing altered sleep architecture and elucidate underlying mechanisms.
Read CV Catherine PaiceECSS Paris 2023: CP-AP23
INTRODUCTION: Menstrual cycle (MC) phases are hypothesized to influence endurance performance through effects on several physiological processes. Recent evidence indicates that differences in performance-related measures between MC phases are trivial or non significant at the group level [1–3]. However, a trivial average effect does not necessarily preclude meaningful effects in individual athletes, as an athlete by phase interaction may be present [4]. Most prior studies monitored only one or two cycles, providing limited statistical power to detect such interactions. Accordingly, using a longitudinal repeated measures design across six consecutive MCs, this study aimed to assess the effect of MC phase on endurance performance in runners, evaluating both the group average effect and individual responses. METHODS: Twenty-three eumenorrheic, trained endurance athletes completed an incremental treadmill test, followed by two 2000-m time trials per MC (early follicular phase, midluteal phase). MC phase was estimated via menstrual tracking and verified for ovulation using luteinizing-hormone testing. Outcome measures were average 2000-m speed and rating of perceived exertion (RPE; Borg 6–20 scale), with RPE assessed immediately after each run. Between phase differences were analyzed using linear mixed effects models including participant as a random effect. The significance level was set at 𝛼 ≤ .05. RESULTS: Sixteen participants (age: 25.4 ± 3.1 years; maximal oxygen consumption: 56.8 ± 6.0 ml/kg/min; 2000m speed: 14.2 ± 1.2 km/h) provided performance data for at least two complete MCs and were included in the analysis. No participant withdrew or missed trials because of MC related symptoms. At the group level, the effect of MC phase was non-significant for both outcomes (2000-m speed: 0.0 [95% CI: –0.1, 0.1] km/h, p = 0.73; RPE: 0 [–1, 0] units, p = 0.70). The athlete by phase interaction accounted for a small proportion of overall variance in phase differences (2000-m speed: 8%; RPE: 24%), indicating no substantial individual responses to phase, particularly for 2000-m speed. CONCLUSION: The present study found no evidence of a meaningful effect of MC phase on 2000-m running performance or RPE at either the group or individual level in trained, eumenorrheic endurance athletes. These findings suggest that routine, phase-based adjustments to training or performance expectations may not be necessary for similar athletes. Limitations include MC phase estimation via tracking and luteinizing-hormone testing rather than continuous hormonal profiling, meaning atypical hormone patterns cannot be ruled out. Future studies should replicate these results with larger samples, and using direct MC phase assessment. [1] Taylor 2024/ [2] Docter 2025/ [3] Taylor 2026/ [4] Hecksteden 2015
Read CV Lisa-Maria PfleidererECSS Paris 2023: CP-AP23