title: The effects of caffeine ingestion on the reaction time and short-term maximal performance after 36 h of sleep deprivation.
abstract: The aim of the present study was to investigate the effects of caffeine ingestion on cognitive and physical performances after 36h of sleep deprivation. In randomized order, thirteen healthy male physical education students (age: 21.1±1.1years, body mass: 77.1±7.2kg, height: 1.77±0.06m) completed four test sessions at 18:00h: after placebo or 5mg·kg(-1) of caffeine ingestion during a baseline night (RN) (bed time: from 22:30h to 07:00h) or a night of 36h of sleep deprivation (TSD). During each test session, participants performed the squat jump (SJ), the reaction time, and the 30-s Wingate tests (i.e., for the measurement of the peak (PP) and mean (MP) powers and the fatigue index (FI)). The results showed that PP and MP decreased and FI increased during the TSD compared to RN in the placebo condition (p<0.001). The caffeine ingestion improved PP after TSD compared to RN (p<0.001). SJ decreased significantly after the TSD compared to RN after both placebo and caffeine ingestions (p<0.001). However, SJ increased significantly after caffeine ingestion during RN and TSD (p<0.001). The reaction time increased significantly after TSD compared to RN (p<0.001). However, the reaction time decreased significantly after the caffeine ingestion only during the TSD (p<0.001). Therefore, caffeine is an effective strategy to counteract the effect of 36h of sleep loss on physical and cognitive performances.
authors.affiliation: Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia. Electronic address: makramsouissi@yahoo.fr.
authors.forename: Makram
authors.initials: M
authors.lastname: Souissi
authors.affiliation: Research Laboratory "Sport Performance Optimization", National Centre of Medicine and Sciences in Sport (CNMSS), Tunis, Tunisia; High Institute of Sport and Physical Education, Sfax University, Sfax, Tunisia.
authors.forename: Hamdi
authors.initials: H
authors.lastname: Chtourou
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Sousse, Tunisia.
authors.forename: Salma
authors.initials: S
authors.lastname: Abedelmalek
authors.affiliation: Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia.
authors.forename: Imen Ben
authors.initials: IB
authors.lastname: Ghozlane
authors.affiliation: Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia.
authors.forename: Zouhair
authors.initials: Z
authors.lastname: Sahnoun
mesh_terms: D000339:Affect / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects*; D005221:Fatigue / Q000188:drug therapy; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000187:drug effects*; D012892:Sleep Deprivation / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine
keywords: Anaerobic performance; Caffeine; Reaction time; Sleep deprivation