title: Effects of time-of-day and partial sleep deprivation on short-term maximal performances of judo competitors.
abstract: This study assessed the effects of partial sleep deprivation on short-term maximal performances of judokas in the morning and afternoon of the following day. In a randomized design, 12 judokas completed the maximal voluntary contraction, the handgrip, and the Wingate tests before and after a judo combat. Measurements were performed at 09:00 and 16:00 hours after a reference-normal sleep night and 2 conditions of 4-hour partial sleep deprivation timed at the beginning (SDB) or at the end of the night (SDE). The results showed that muscle power and strength were significantly higher at 16:00 than 09:00 hours (p < 0.05). These diurnal variations disappeared after SDB and SDE and after the combat. In addition, SDE resulted in significant decreases of short-term maximal performance in the afternoon (p < 0.01). In conclusion, SDE decreased muscle strength and power at 16:00 hours and, therefore, might have blunted the diurnal variations of short-term maximal exercise. Thus, early rising is more detrimental than late bedtime to muscle strength and power for judo athletes when competitions are scheduled in the afternoon hours.
authors: Research Laboratory Sports performance Optimization, National Center of Medicine and Science in Sports, Tunis, Tunisia. n_souissi@yahoo.fr
authors: Nizar
authors: N
authors: Souissi
authors: Hamdi
authors: H
authors: Chtourou
authors: Asma
authors: A
authors: Aloui
authors: Omar
authors: O
authors: Hammouda
authors: Mohamed
authors: M
authors: Dogui
authors: Anis
authors: A
authors: Chaouachi
authors: Karim
authors: K
authors: Chamari
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D016139:Martial Arts / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D012892:Sleep Deprivation / Q000503:physiopathology*; D013997:Time Factors