Author(s): GURUHAN, S., GÜZEL, N., HIRATA, R., TOR, Ö., ANDREUCCI, A., RATHLEFF, M., Institution: GAZI UNIVERSITY, Country: TURKEY, Abstract-ID: 1980

INTRODUCTION:
Sleep is a critical factor for neuromuscular recovery and optimal physical performance, and sleep deprivation has been shown to increase perceived exertion and accelerate exhaustion during high-intensity exercise. However, the extent to which sleep deprivation contributes to central and peripheral fatigue remains unclear. Therefore, this study aimed to investigate the effects of acute sleep deprivation on hamstring and quadriceps muscle fatigue during eccentric exercise.
METHODS:
A total of 19 recreationally active participants (9 males and 10 females; mean ± SD age: 21.05 ± 1.46 years; body mass: 21.99 ± 2.89 kg) with good sleep quality, determined using the Pittsburgh Sleep Quality Index and a 5-point Likert scale, were recruited for this randomized crossover study. Each participant completed two experimental sessions separated by a 2-week washout period. The first session was conducted 2 hours after awakening under habitual sleep conditions. The second session was performed at the same time of day following 24 hours of total sleep deprivation. The testing protocol consisted of a Maximum Voluntary Isometric Contraction (MVIC) for normalization purposes, followed by an isokinetic eccentric exercise protocol. The amount of fatigue in the hamstring and quadriceps muscle groups during 15 repetitions of isokinetic eccentric contraction was determined using the slope value (slope coefficient) of muscle activation in normal sleep and sleep deprivation conditions. The obtained data were analyzed using the dependent groups t-test.
RESULTS:
The amount of fatigue occurring in the RF muscle as a result of 15 repetitions of eccentric contraction was statistically higher after sleep deprivation intervention compared to normal sleep (p=0.018). There was no statistically significant difference in fatigue between normal sleep and sleep deprivation conditions in the VM, VL, BF, and ST muscles (p>0.05).
CONCLUSION:
This study showed that 24 hours of total sleep deprivation significantly increased fatigue in the rectus femoris muscle during repeated eccentric contractions, while no significant differences were observed in the other hamstring and quadriceps muscles. These findings suggest that sleep deprivation may have muscle-specific effects rather than causing a generalized increase in lower extremity fatigue. Therefore, acute sleep loss may negatively influence certain aspects of neuromuscular performance.