Author(s): BOFFET, A., BEAUCHAMPS, V., PONTIGGIA, A., DESCHODT-ARSAC, V., SAUVET, F., Institution: IMS LABORATORY, Country: FRANCE, Abstract-ID: 1545

INTRODUCTION
In extreme endurance sports, athletes face simultaneous physical and cognitive demands under conditions of sleep deprivation, which may compromise performance during prolonged competitions. Acute sleep loss impairs physical endurance [1] and cognitive functions [2] particularly attentional processes. Understanding vulnerability to sleep loss and recovery capacity is therefore essential to optimize performance management. The present study investigated the effects of a progressive four-day sleep restriction protocol on cognitive performance, subjective perception, and inter-individual variability.
METHODS
Thirty-six participants (16 men, 20 women; 32 ± 7 years) completed a protocol consisting of 8h reference sleep (REF), total sleep deprivation (TSD), 3h restricted sleep recovery (RSR), and 8h recovery sleep (RECOV). Actigraphy during the seven days preceding the protocol provided baseline sleep activity. Participants performed high cognitive-demand tasks assessing multitasking (MATB-II), attention networks (ANT), sustained attention (PVT), processing speed (DGSS), and vigilance in a driving simulator (MRDS). Performance outcomes included accuracy, reaction times, lapses, precision and driving stability. Subjective measures included perceived workload (NASA-TLX), sleepiness (KSS), and mood (POMS). Repeated-measures ANOVAs (or Friedman tests) assessed sleep condition effects (α=0.05). Correlation analyses and principal component analyses (PCA) were conducted to explore individual susceptibility to deprivation and recovery capacity by integrating baseline sleep parameters, cognitive performance changes, and subjective responses.
RESULTS
Sleep condition affected all cognitive metrics (p<0.001). TSD induced impairments in reaction time, accuracy, lapses, and driving stability (p < 0.05). RSR led to performance recovery relative to TSD (p < 0.05). Only vigilance tasks highly sensitive to microsleep episodes, such as MRDS, remained impaired (p=0.99). Subjective sleepiness, workload, and mood followed a similar pattern. After RECOV, both objective and subjective measures returned to baseline. Multivariate analyses revealed correlations (0.50 < r < 0.70) between habitual sleep duration, individual characteristics, cognitive performance changes, and perceived effort, with distinct association patterns after TSD versus RSR.
DISCUSSION
Total sleep deprivation impairs attentional processes, whereas restricted sleep recovery restores many functions but leaves vigilance partly impaired. Inter-individual variability, linked to habitual sleep patterns and personal traits, reveals distinct susceptibility and recovery profiles. These findings support the use of integrative multivariate approaches to better optimize sleep management strategies in contexts combining prolonged physical and cognitive demands.
REFERENCES
1. Lopes P, et al., European Journal of Sport Science, vol. 23, juill. 2023
2. Wüst LN, et al., Sleep Medicine Reviews, vol. 76, août 2024