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Hermassi S.,University of Sfax | Chelly M.S.,University of Sfax | Chelly M.S.,Manouba University | Tabka Z.,University of Sfax | And 3 more authors.
Journal of Strength and Conditioning Research | Year: 2011

Hermassi, S, Chelly,MS, Tabka,Z, Shephard, RJ, andChamari, K. Effects of 8-week in-season upper and lower limb heavy resistance training on the peak power, throwing velocity, and sprint performance of elite male handball players. J Strength Cond Res 25(9): 2424-2433, 2011-The aims of this study were to test the potential of in-season heavy upper and lower limb strength training to enhance peak power output (W peak), vertical jump, and h ndball related field performance in elite male handball players who were apparently already well trained, and to assess any adverse effects on sprint velocity. Twentyfour competitors were divided randomly between a heavy resistance (HR) group (age 2060.7 years) and a control group (C; age 20 ± 0.1 years). Resistance training sessions were performed twice a week for 8 weeks. Performance was assessed before and after conditioning. Peak power (W peak) was determined by cycle ergometer; vertical squat jump (SJ) and countermovement jump (CMJ); video analyses assessed velocities during the first step (V 1S), the first 5 m (V 5m), and between 25 and 30 m (V peak) of a 30-m sprint. Upper limb bench press and pull-over exercises and lower limb back halfsquats were performed to 1-repetition maximum (1RM). Upperlimb, leg, and thigh muscle volumes and mean thigh crossse ctional area (CSA) were assessed by anthropometry. W peak (W) for both limbs (p < 0.001), vertical jump height (p < 0.01 for both SJ and CMJ), 1RM (p,0.001 for both upper and lower limbs) and sprint velocities (p < 0.01 for V 1S and V 5m; p < 0.001 for V peak) improved in the HR group. Upper body, leg, and thigh muscle volumes and thigh CSA also increased significantly after stre gth training. We conclude that in-season biweekly heavy back half-squat, pull-over, and bench-press exercises can be commended to elite male handball players as improving many m asures of handball-related performance without adverse effects upon speed of movement. © 2011 National Strength and Conditioning Association. Source


Abedelmalek S.,University of Sfax | Chtourou H.,Research Laboratory Sports Performance Optimization | Aloui A.,Research Laboratory Sports Performance Optimization | Souissi N.,Research Laboratory Sports Performance Optimization | Souissi N.,Manouba University
European Journal of Applied Physiology | Year: 2013

The present study was designed to evaluate the effect of time of day and partial sleep deprivation (PSD) on short-term maximal performance and level of interleukin-6 (IL-6) in trained subjects. In a randomized order, 12 football players were asked to perform a 30-s Wingate test during which we measured the peak (PP) and mean (MP) powers. Measurements were performed at 0800 and 1800 hours, after two nocturnal regimens: (1) a reference normal sleep night (RN) and (2) 4 h of PSD caused by an early awakening. Plasma IL-6 concentrations were measured before (P1), immediately after (P2), and 60 min after the exercise (P3). PP and MP improved significantly from the morning to the afternoon after RN (P < 0.05) and from the afternoon to the morning after PSD (P < 0.05). Compared to RN, PP and MP were not affected by PSD the following morning. However, there was a significant decrease in PP and MP (P < 0.001) after the PSD at 1800 hours. In all conditions, IL-6 and resting core temperature were significantly higher (P < 0.05) in the afternoon than in the morning. In all sessions, IL-6 levels increased significantly from P1 to P2 (P < 0.01) and remained elevated in the afternoon during the recovery period after PSD (P < 0.05). However, no significant difference was observed in IL-6 between P1 and P3 during RN and PSD at 0800 hours. In conclusion, a short-term high-intensity exercise may increase the IL-6 concentrations in the morning and the afternoon. Moreover, IL-6 remained elevated during the recovery period in the afternoon after the PSD at the end of the night. © 2012 Springer-Verlag. Source


Souissi N.,Research Laboratory Sports Performance Optimization | Souissi N.,Manouba University | Chtourou H.,Research Laboratory Sports Performance Optimization | Chtourou H.,University of Sfax | And 5 more authors.
Journal of Strength and Conditioning Research | Year: 2013

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. © 2013 National Strength and Conditioning Association. Source


Chtourou H.,Research Laboratory Sports Performance Optimization | Chtourou H.,University of Sfax | Souissi N.,Research Laboratory Sports Performance Optimization | Souissi N.,Manouba University
Journal of Strength and Conditioning Research | Year: 2012

This article focuses on physical performances after training at a specific time of day. To date, although the effect of time of day on aerobic performances appears to be equivocal, during anaerobic exercises, the effect of time of day has been well established with early morning nadirs and peak performances in the late afternoon. These diurnal rhythms can be influenced by several factors such as the regular training at a specific time of day. Indeed, regular training in the morning hours may increase the lower morning performances to the same or even higher level as their normal diurnal peak typically observed in the late afternoon by a greater increase of performance in the evening. However, regular training in the evening hours may increase the morning-evening (i.e., amplitude of the rhythm) difference by a greater increase of performance in the late afternoon. Therefore, adaptations to training are greater at the time of day at which training is regularly performed than at other times. Nevertheless, although modifications in resting hormones concentrations could explain this time-of-day specific adaptations, precise information on the underlying mechanisms is lacking. © 2012 National Strength and Conditioning Association. Source


Castagna C.,University of Rome Tor Vergata | Impellizzeri F.M.,Schulthess Klinik | Chaouachi A.,Research Laboratory Sports Performance Optimization | Bordon C.,Palermo Football Club | Manzi V.,University of Rome Tor Vergata
Journal of Strength and Conditioning Research | Year: 2011

Castagna, C, Impellizzeri, FM, Chaouachi, A, Bordon, C, and Manzi, V. Effect of training intensity distribution on aerobic fitness variables in elite soccer players: A case study. J Strength Cond Res 25(1): 66-71, 2011 - The aim of this article was to quantify the distribution of training intensities and its effect on aerobic fitness in professional elite soccer players. Fourteen professional soccer players were observed during the prechampionship training period (6 weeks). Treadmill running speed and heart rates (HRs) at 2 and 4 mmol · L -1 blood-lactate concentrations were assessed pre and posttraining. Training intensities were categorized using 3 HR zones: low intensity (


HR 4 mmol · L -1). Analysis of the 504 individual training sessions showed that 73 ± 2.5, 19 ± 2.8, and 8 ± 1.4% of the total training time was spent at low, moderate, and high intensity, respectively (p < 0.001). Speed at 2 and 4 mmol · L -1 significantly improved posttraining (5 and 7%, respectively, p < 0.01). Training spent at high intensity was significantly related to relative speed improvements at 2 mmol · L -1 (r = 0.84, p < 0.001;) and 4 mmol · L -1 (r = 0.65, p = 0.001). Players spent almost two-thirds of their training time at low intensities. However, only the time spent at high intensity (>90% of maximal HR) was related to changes in aerobic fitness. These results support the usefulness of the quantification of aerobic training load using HR. Furthermore, it stresses the effectiveness of the high-intensity training in soccer. © 2011 National Strength and Conditioning Association. Source

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