Souissi, N, Chtourou, H, Aloui, A, Hammouda, O, Dogui, M, Chaouachi, A, and Chamari, K. Effects of time-of-day and partial sleep deprivation on short-term maximal performances of judo competitors. J Strength Cond Res 27(9): 2473–2480, 2013—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.
1Research Laboratory “Sports performance Optimization”, National Center of Medicine and Science in Sports, Tunis, Tunisia
2High Institute of Sport and Physical Education, Ksar-Saïd, Manouba University, Tunis, Tunisia
3Research Unit (EM2S), High Institute of Sport and Physical Education, Sfax University, Sfax, Tunisia
4Research Unit “Neurophysiology of vigilance, of attention and performances”, Service of functional exploration of the nervous system, CHU Sahloul, Sousse, Tunisia
5Research and Education Center, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
Address correspondence to Dr. Nizar Souissi, firstname.lastname@example.org.