A study conducted during the 2024 Race Across France demonstrates a direct link between sleep duration and race performance among ultra-cyclists. Riders who averaged more sleep per 24-hour period achieved better placings. Those who slept less than 5.29 hours a day suffered from increasing fatigue and impaired cognitive function. Reaction times slowed particularly between 5 am and 9 am, whilst the highest level of sleepiness was observed between midnight and 4 am.
