0755 Sleep Strategies and Sleep-related Adverse Events Experienced by Runners in 200-mile Ultramarathons

Abstract Introduction Sufficient sleep is essential for the athletic recovery process and is considered foundational for optimal sports performance. Participation in ultramarathons taking place over multiple days may benefit from specific sleep strategies to avoid sleep-related adverse events and injury. This study aimed to identify if and which types of sleep strategies were used by ultramarathon runners, whether these were associated with sleep-related adverse events or injury, and the types of sleep-related adverse events experienced during these races. Methods This cross-sectional study comprised an electronic survey distributed to ultramarathoners aged 18 years or above who had recently completed a 200-plus mile race. Survey distribution was facilitated by race directors between June and September 2023. The survey included questions about demographics, ultramarathon experience, training habits, sleep-related factors, sleep-related adverse events experienced during the race, and whether an injury was sustained. Continuous variables were summarized as mean (standard deviation) and categorical variables as N (%). Logistic regression was used to quantify associations between sleep strategies and sleep-related adverse events and injury. Results Of 115 survey respondents who competed in a 200-plus mile ultramarathon, mean (standard deviation) age was 47.5 (10.8) and 67.0% were men. Among 71 respondents (61.7%) who reported using a sleep strategy during the race, the most common was ‘sleeping when exhausted’ (N=31; 43.7%) and the least common was sleeping for 6-8 hours (N=3; 4.2%). Using a strategy of ‘sleeping when exhausted’ was significantly associated with having a sleep-related adverse event (odds ratio 3.5, 95% confidence interval 1.3-9.5, p=0.01) but was not associated with sustaining an injury during the race (odds ratio 0.7, 95% confidence interval 0.2-2.1, p=0.5). Of 42 people who reported experiencing a sleep-related adverse event, the most common was experiencing hallucinations (N=40; 95.2%). Conclusion Sleeping when exhausted during an ultramarathon was a common strategy associated with experiencing hallucinations during the race. Further investigation should determine whether this is perceived as problematic for runners or if this is an integral part of their ultramarathon experience. Longitudinal research into acute, sub-acute and chronic downstream sequalae of sleep deprivation in this athletic population is warranted. Support (if any)