Sleep is a cornerstone of cognitive and physical functioning and is consistently ranked as the most important recovery strategy. Yet research shows that elite athletes often experience reduced sleep duration and quality. Emerging data suggest that although women may exhibit better objective sleep patterns, female athletes report poorer subjective sleep quality and a higher prevalence of sleep disturbances. In parallel, diurnal variations in performance have long been recognized, with evening performance generally surpassing morning levels. Individual differences in circadian phenotype further modulate these patterns, influencing physiological markers. This invited session explores the intersection of chronobiology and sport science. The first presentation offers an overview of human chronobiology and its implications in athletic performance. The second highlights emerging research on sleep in female athletes, addressing the potential need for sex-specific considerations. The final presentation focuses on practical interventions to manage sleep deprivation, with direct applications for athletes and sport practitioners. The session provide san interdisciplinary perspective on optimizing recovery and performance through sleep and biological timing. Overall, the session is relevant for sport scientists, and practitioners seeking evidence-based strategies to optimize recovery and performance through chronobiological and sleep-related interventions.
ECSS Paris 2023: IS-AP02
Humans are rhythmical animals, who have developed through evolution anatomy and physiology to support wakefulness in the daytime and inactivity and sleep during the nighttime. The body clock located in the superchiasmatic nucleus is likened to a conductor in an orchestra, keeping the molecular and protein clocks located in all tissue at the same time and rhythm through complex feedback loops. Elegant experiments have shown that the body clock rather than being an exact time mechanism has a natural propensity to delay (~0.3 h) (Chadwick, 2008). Therefore, requiring input from environmental factors (zeitgebers – time cues) such as light, activity/exercise, nutrition and melatonin (originating from the pineal gland) to keep in a 24-h time frame (Hastings et al., 2018). Knowledge of the appropriate timing of the stimulus according to a phase response curve for these time givers enables us to adjust rhythms. This enables advice to be given for rhythm disturbances such as shiftwork or trans-meridian travel (Waterhouse et al., 2007). Sleep serves three main functions, for cellular restitution and healing (predominantly in the first half of sleep), memory consolidation (in the second half) and removal of toxins from the brain. If we accept that the full purpose of sleep is still not completely understood, we can at least agree that normal human sleep comprises two main types – non-rapid eye movement sleep (non-REM) and REM (rapid eye movement) sleep4. Classically non-REM sleep is divided into three stages, representing a continuum from “light” sleep (stages N1 and N2), through to “deep” sleep (stage N3, also known as slow wave sleep). The composition and duration of normal sleep changes across the life cycle. Indirect markers of the activity of the body clock such as melatonin and core body temperature have been used, with a minimum in core temperature observed at 04-05 h and peaks ~17 h. In research where a standardised protocol has been employed cognitive and sporting performance in athletic populations shows a time-of-day effect, with cognitive (decision making etc) peaking from 12-14 h. But motivation to perform maximally and gross muscular performance (repeated sprints, Time-trial etc) peaking in the evening around the peak in core body temperature (17-19 h). This presentation will cover the basic concepts of rhythmicity, introduce the location and properties of the body clock. We will then consider the functions of sleep and implications for diurnal variations in athletic performance. Chadwick, D. J. (2008). Circadian clocks and their adjustment. New Jersey: John Wiley & Sons. Hastings, M. H., Maywood, E. S., and Brancaccio, M. (2018). Generation of circadian rhythms in the suprachiasmatic nucleus. Nature Reviews Neuroscience, 19(8), 453-469. doi:10.1038/s41583-018-0026-z Waterhouse, J., Reilly, T., Atkinson, G., and Edwards, B. (2007). Jet lag: trends and coping strategies. Lancet, 369(9567), 1117-1129. doi:Doi 10.1016/S0140-67
Read CV Ben EdwardsECSS Paris 2023: IS-AP02
It is well established that athletes often experience challenges to obtaining optimal quality and quantity of sleep. Data in female and male athletes suggest some differences in both objective and subjective sleep outcomes. The biological processes that occur during sleep might be influenced by endogenous hormone concentrations across a menstrual cycle and exogenous hormones from hormonal contraception. Receptors for estrogen and progesterone are found in areas of the brain that are also involved in sleep regulation. Therefore, there is potential that sleep characteristics may be different at different time points during the menstrual cycle and in athletes experiencing menstrual cycle dysfunction. This has timing implications for research that investigates interventions aimed to enhance sleep as well potential management of menstrual cycle symptoms to optimise sleep. This presentation will describe recent findings describing sleep characteristics in female athletes, including those who are naturally-cycling and those using hormonal contraception. The role of hormone concentrations and menstrual cycle symptoms will be discussed. Targeted at sports scientists, researchers and professionals working with elite and recreational female athletes, this presentation aims to provide clarity around whether the menstrual cycle, symptoms and ovarian hormones influence sleep. This presentation will provide audience members with the latest information on sleep habits of female and male elite and recreational athletes and describe the potential influence of gender on sleep. This can provide researchers and practitioners with information regarding whether the menstrual cycle, use of hormonal contraception and associated symptoms, should be considered when assessing sleep and sleep interventions.
Read CV Shona HalsonECSS Paris 2023: IS-AP02
Sleep is a cornerstone of athletic performance, health, and overall well-being. Despite its recognized importance, most elite athletes fail to achieve the recommended 7–9 hours of nightly sleep and often sleep less than the general population. This shortfall is driven by multiple factors, including demanding training schedules, frequent travel, competition stress, and late-night competition, all of which disrupt normal sleep patterns. Sleep deficiency has been associated with impaired physical and neurocognitive performance, increased fatigue, and a higher risk of illness, making effective sleep management a critical component of athlete care. To address these challenges, several interventions have been implemented in elite sport, such as strategic napping, sleep hygiene education, and sleep extension protocols. However, evidence regarding their efficacy and long-term effectiveness remains limited. Most studies on sleep hygiene and education have been short-term (≤4 weeks) and, while they show modest improvements in sleep duration, their impact on performance and perceived recovery is equivocal. Sustained implementation of sleep hygiene strategies requires behavioural change, highlighting the need for extended monitoring periods. Furthermore, interventions applied to athletes who already achieve 7–8 hours of sleep may yield minimal benefit, as baseline sleep was within recommended ranges. Daytime napping is a widely used compensatory strategy among athletes to extend total sleep duration within a 24-hour period and alleviate daytime sleepiness caused by sleep restriction (Lastella et al., 2021). Research consistently shows that naps reduce sleepiness, enhance alertness, and yield positive effects on physical and cognitive performance, as well as psychological state and perception. While benefits are evident in well-rested athletes, improvements in physical, cognitive, and mood-related outcomes appear even greater in athletes experiencing sleep restriction (Lastella et al., 2021). Implementing sleep interventions in elite sport remains challenging due to logistical constraints and demanding schedules that often conflict with conditions conducive to optimal sleep. Therefore, a targeted, individualized approach—rather than a “one-size-fits-all” model—is recommended for athletes struggling to meet sleep recommendations. This presentation will provide an overview of current evidence on sleep interventions, discuss practical strategies for mitigating sleep deprivation, and identify key gaps in research to guide future practice in high-performance environments. Lastella, M., Halson, S. L., Vitale, J. A., Memon, A. R., and Vincent, G. E. (2021). To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance. Nat Sci Sleep, 13, 841-862. doi:10.2147/NSS.S315556
Read CV Sabrina ForsterECSS Paris 2023: IS-AP02