Purpose: To investigate the effects of napping after partial sleep deprivation (PSD) on reaction time, mood, and biochemical response to repeated-sprint exercise in athletes. Methods: Nine male judokas performed 4 test sessions in a counterbalanced and randomized order. Participants accomplished 1 control session after a normal sleep night (NSN) and 3 after PSD with (1) no nap, (2) ∼20-min nap (N20), and (3) ∼90-min nap (N90) opportunities. Test sessions included the running-based anaerobic sprint test, reaction time, Hooper index, and Epworth Sleepiness Scale. Muscle-damage biomarkers and antioxidant status were evaluated before and after exercise. Results: PSD decreased maximum (P < .001, d = 1.12), mean (P < .001, d = 1.33), and minimum (P < .001, d = 1.15) powers compared with NSN. However, N20 and N90 enhanced maximum power compared with PSD (P < .05, d = 0.54; P < .001, d = 1.06, respectively). Minimum power and mean power increased only after N90 (P < .001, d = 1.63; P < .001, d = 1.16, respectively). Epworth Sleepiness Scale increased after PSD (P < .001, d = 0.86) and decreased after N20 (P < .001, d = 1.36) and N90 (P < .001, d = 2.07). N20 reduced multiple-choice reaction time (P < .001, d = 0.61). Despite performance decrement, PSD increased postexercise aspartate aminotransferase (P < .001, d = 4.16) and decreased glutathione peroxidase (P < .001, d = 4.02) compared with NSN. However, the highest performances after N90 were accompanied with lesser aspartate aminotransferase (P < .001, d = 1.74) and higher glutathione peroxidase (P < .001, d = 0.86) compared with PSD. Conclusions: Napping could be preventive against performance degradation caused by sleep loss. A short nap opportunity could be more beneficial when the subsequent effort is brief and requires frequent decision making. However, a longer nap opportunity could be preventive against muscle and oxidative damage, even for higher performances.
Mohamed Romdhani, Nizar Souissi, Yassine Chaabouni, Kacem Mahdouani, Tarak Driss, Karim Chamari and Omar Hammouda
Hichem Souissi, Anis Chaouachi, Karim Chamari, Mohamed Dogui, Mohamed Amri and Nizar Souissi
The purpose of this study was to examine the time-of-day effects on short-term performances in boys. In a balanced and randomized study design, 20 boys performed four anaerobic tests of strength and power (grip strength, Squat-Jump, Five-jump and cycle Wingate tests) at 08:00, 14:00 and 18:00 hr on separate days. The results showed a time-of-day effect on oral temperature. Analysis of variance revealed a significant time-of-day effect for short-term performances for strength, cycle, and jump tests. The post hoc analysis revealed that performances improved significantly from morning to afternoon but no significant differences were noticed between 14:00 and 18:00 hr. The differences between the morning and the afternoon (the highest value measured either at 14:00 or at 18:00 hr) reached 5.9% for grip strength, 3.5% for the squat jump test, 5% for the five jump test, and 5.5% for Ppeak and 6% for Pmean during the Wingate test. A significant positive correlation was found between temperature and short-term performances. In conclusion, a time-of-day effect in the child’s maximal short-term exercise performances exists in relation with core temperature. Such variations would have pronounced effects when expressed in training programs and competitions.
Hichem Souissi, Hamdi Chtourou, Anis Chaouachi, Mohamed Dogui, Karim Chamari, Nizar Souissi and Mohamed Amri
The aim of this study was to assess the effect of time-of-day-specific training on the diurnal variations of short-term performances in boys. Twenty-four boys were randomized into a morning-training-group (07:00–08:00h; MTG), an evening training-group (17:00–18:00h; ETG) and a control-group (CG). They performed four tests of strength and power (unilateral isometric maximal voluntary contraction of the knee extensor muscles, Squat-Jump, Counter-Movement-Jump and Wingate tests) at 07:00 and 17:00h just before (T0) and after 6 weeks of resistance training (T1). In T0, the results revealed that short-term performances improved and oral temperature increased significantly from morning to afternoon (amplitudes between 2.36 and 17.5% for both oral temperature and performances) for all subjects. In T1, the diurnal variations of performances were blunted in the MTG and persisted in the ETG and CG. Moreover, the training program increase muscle strength and power especially after training in the morning hours and the magnitude of gains was greater at the time-of-day-specific training than at other times. In conclusion, these results suggest that time-of-day-specific training increases the child’s anaerobic performances specifically at this time-of-day. Moreover, the improvement of these performances was greater after morning than evening training.
Bent R. Rønnestad and Joar Hansen
training including blocks of LIT, MIT, and HIT. The training program was based on observations of endurance-performance-enhancing effects of a large portion of LIT and smaller but substantial proportions of both MIT and HIT, 1 BP, 2 , 3 heavy strength training, 4 short-term performance peaking, 5 and
Paul Comfort, Thomas Dos’Santos, Paul A. Jones, John J. McMahon, Timothy J. Suchomel, Caleb Bazyler and Michael H. Stone
Strength Cond Res . 2004 ; 18 : 792 – 795 . PubMed ID: 15574085 15574085 28. Harris GR , Stone M , O’Bryant HS , Proulx CM , Johnson R . Short-term performance effects of high power, high force or combined weight training methods . J Strength Cond Res . 2000 ; 14 : 14 – 20 . 29. Cormie
Iñigo Mujika, Luis Villanueva, Marijke Welvaert and David B. Pyne
optimal overload and taper in elite swimmers over time . J Sports Sci Med . 2013 ; 12 : 668 – 678 . PubMed ID: 24421726 24421726 15. Rønnestad BR , Hansen J , Vegge G , Mujika I . Short-term performance peaking in an elite cross-country mountain biker . J Sports Sci . 2017 ; 35 : 1392
Nick Dobbin, Richard Hunwicks, Ben Jones, Kevin Till, Jamie Highton and Craig Twist
.1080/02640410903348657 28. Hopkins WG . Spreadsheets for analysis of controlled trials with adjustment for a subject characteristic . Sportscience . 2006 ; 10 : 46 – 50 . 29. Harris GR , Stone MH , O’Bryant HS , Proulx CM , Johnson RL . Short-term performance effects of high power, high force, or
Anna Sverdlik, Robert J. Vallerand, Ariane St-Louis, Michael Sam Tion and Geneviève Porlier
temporal reflection in more immediate, short-term performance outcomes. Although this is not a widely studied outcome, previous sport research had investigated observed last-second performance under names such as “buzzer beater” (e.g., Baker, 2008 ; Fontanella, 2006 ) and “penalty shot” (e.g., Geisler
Nicki Winfield Almquist, Gertjan Ettema, James Hopker, Øyvind Sandbakk and Bent R. Rønnestad
M , Nielsen LR , Bangsbo J . Effect of intensified training on muscle ion kinetics, fatigue development, and repeated short-term performance in endurance-trained cyclists . Am J Physiol Regul Integr Comp Physiol . 2013 ; 305 ( 7 ): R811 – R821 . PubMed ID: 23883682 doi:10.1152/ajpregu.00467
Kevin M. Carroll, Jake R. Bernards, Caleb D. Bazyler, Christopher B. Taber, Charles A. Stuart, Brad H. DeWeese, Kimitake Sato and Michael H. Stone
motivated throughout the entirety of the intervention. References 1. Harris GR , Stone MH , O’Bryant HS , Proulx CM , Johnson RL . Short-term performance effects of high power, high force, or combined weight-training methods . J Strength Cond Res . 2000 ; 14 ( 1 ): 14 – 20 . doi:10