Salma Abedelmalek

Effects of Partial Sleep Deprivation on Proinflammatory Cytokines, Growth Hormone, and Steroid Hormone Concentrations During Repeated Brief Sprint Interval Exercise

The purpose of this study was to evaluate the effects of partial sleep deprivation (PSD) on circulating concentrations of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in relation to the secretory profiles of growth hormone (GH), cortisol, and testosterone during a repeated brief sprint interval exercise. Thirty healthy football players (mean age: 21.1 [range: 18–24] years; body mass index [BMI]: 22.6 [range: 18.47–24.46] Kg/m2) completed two test sessions at 08:00 h, one scheduled after a baseline night (bedtime: from 22:30 to 07:00 h) and the other after a PSD night caused by an early awakening (bedtime: from 22:30 to 03:00 h). During each session, participants performed 4 × 250-m run on a treadmill at a constant intensity of 80% of the personal maximal speed with a 3-min recovery in between. Tests session were performed at 08:00 h. Blood samples were collected before, immediately after the first and the fourth 250-m run, and 60 min after the exercise. The results showed that cortisol concentrations were not affected by the PSD. However, GH and testosterone concentrations were higher (p < .05) 60 min after the exercise during PSD in comparison with baseline. Likewise, plasma concentrations of IL-6 and TNF-α were higher (p < .05) after PSD during the exercise (i.e., the first and the fourth run) and remained elevated during the recovery period (i.e., 60 min after the exercise). In conclusion, these results showed that sleep restriction increases the proinflammatory cytokine, GH, and testosterone concentrations after physical exercise but did not affect the cortisol responses. (Author correspondence: n_souissi@yahoo.fr)

Effect of time-of-day and racial variation on short-term maximal performance

The present study was designed to evaluate the effect of time-of-day and racial variation on muscle power and fatigue during a 30-s Wingate test. In a randomized order, 36 footballers – 12 black Tunisians (BT), 12 white Tunisians (WT), and 12 South Africans (SA) were asked to perform a 30-s Wingate test during two experimental sessions, which were either at 08:00 or 17:00 h. At the beginning of each test session, resting core temperature was recorded. Peak (PP) and mean (MP) power as well as the fatigue index (FI) were calculated during the Wingate test. In all groups, core temperature, PP and MP were significantly higher (p < 0.001) in the afternoon than in the morning and considerably more so in SA than in WT and BT (p < 0.05). However, no major difference was observed between WT and BT in regards to all parameters. Also, FI was unaffected by either time-of-day or racial variation. Our results show that the diurnal variation of muscle power during the Wingate test can differ between races.

The effects of caffeine ingestion on the reaction time and short-term maximal performance after 36 h of sleep deprivation

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.

Caloric Restriction Effect on Proinflammatory Cytokines, Growth Hormone, and Steroid Hormone Concentrations during Exercise in Judokas.

The aim of this study was to evaluate the effect of caloric restriction on the immune and hormonal responses during exercise in judo athletes. In a randomised order, 11 male judokas (age: 20.45 ± 0.51; height: 1.71 ± 0.3 m; and body weight: 75.9 ± 3.1 kg) participate in this study during a period of weight maintenance (baseline) and after 7 days of caloric restriction (CR). All subjects performed the Special Judo Fitness Test (SJFT) during the two conditions. Values for nutrient intakes were obtained from a 7 d food record kept during a period of weight maintenance and after a 7-day food restriction (−5~6 MJ/day). Our results showed that CR resulted in significant decreases in body weight (P < 0.05) and performance (P < 0.05). However, heart rate and SJFT index (P < 0.05) increase significantly during CR in comparison to baseline. Moreover, exercise leads to a significant increase in testosterone, cortisol, growth hormone (GH), leukocytes, neutrophils, TNF-α, and IL-6, in both CR and baseline conditions. Compared to baseline, TNF-α and IL-6 were significantly higher during CR condition (P < 0.05). Additionally, CR leads to an increase in cortisol and GH (P < 0.05) and a decrease in testosterone concentrations (P < 0.05).

Effects of time-of-day and caffeine ingestion on mood states, simple reaction time, and short-term maximal performance in elite judoists.

The purpose of this study was to examine the ergogenic effect of caffeine ingestion on the diurnal fluctuations of mood states, simple reaction time, and muscle power during the Wingate test. Twelve elite judoists (age: 21.1 ± 1.2 years; body mass: 83.8 ± 8.2 kg; height: 1.8 ± 0.6 m), participated in the present study. Mood states and simple reaction time, and peak and mean powers (P peak, P mean) during the Wingate test were measured during four separate sessions in a randomized design: at 07:00 and 17:00 h after placebo or caffeine ingestion (i.e. 5 mg/kg). The results of the present study revealed an increase in the anxiety, vigor, and fatigue and a decrease in the simple reaction time after the caffeine compared to the placebo ingestion at 07:00 and 17:00 h. Moreover, the results indicated that the diurnal variation of P peak and P mean was reduced after the ingestion of the caffeine in comparison with the control session by an increased performance only at 07:00 h (p < 0.05). In conclusion, caffeine ingestion is recommended in the morning to minimize the diurnal fluctuations of short-term maximal performance.

The effect of Ramadan intermittent fasting on dynamic postural control in judo athletes

The aim of this study was to evaluate Ramadan intermittent fasting (RIF) effects on dynamic postural control in male judo athletes. In a randomized order, 11 male judokas (22.5 ± 2.8 years, 173.8 ± 6.9 cm, and 70.3 ± 4.4 kg; mean ± SD) were asked to perform four protocols of dynamic postural control, i.e., sit to stand test (STS), step up and over test (SUO), step quick turn test (SQT), and forward lunge test (FL), one week before RIF (BRF), during the second week (SWR) of RIF, and three weeks after RIF (AR). The results of the present study showed that during the dynamic balance tests, the movement time, lift-up index, and impact index during the STS test were significantly higher during SWR in comparison with BRF and AR (p < 0.05). However, those measured during the SUO test appeared independent of RIF. The turn time and turn degree during the SQT test and the distance, the impact index, the contact time, and the force impulse increased significantly from BRF and AR to the SWR (p < 0.05). However, no significant difference was observed in all tests (i.e. STS, SUO, SQT, and FL) between BRF and AR. In conclusion, the present study suggested that RIF may negatively affect the postural control of judo athletes.

The effect of strength training by electrostimulation at a specific time of day on immune response and anaerobic performances during short-term maximal exercise

Abstract The aim of this study was to evaluate the effect of electrostimulation strength training (ES) and time-of-day on immune response and anaerobic performances during short-term maximal exercise. In randomized order, 24 active men divided into three groups: MTG (n=8): training times 07:00–08:00h; ETG (n=8): training times 17:00–18:00h; and CG (n=8) and were asked to perform a 30-s Wingate test (i.e. peak (PP), mean (MP)) and strength (1-RM) before (T0) and after four weeks of training (T1) at 08:00h and 18:00h. Our results showed that oral temperature, PP (p<0.05), MP (p<0.05), and Interleukine-6 levels (IL-6) (p<0.001) were significantly higher at 18:00h compared to 08:00h in all groups. However, 1-RM was not affected by the time-of-day (p>0.05). Likewise, IL-6 increased after exercise at T0 and T1 in CG, ETG, and MTG (p<0.001). Moreover, ES training leads an improvement in performances (p<0.05) with an increase in the tight circumference for the MTG (p<0.01) at the same time-of-training (08:00h) without affecting the immune response (p>0.05). In fact, the amplitude of variation was disappeared in MTG after ES. However, the ES did not affect the PP, MP, and 1-RM in ETG with no change in the tight circumference. A significant increase in IL-6 at the same time-of-training (p<0.05) was observed on ETG. For CG, no significant change was observed after ES compared with pre-training. In conclusion, ES training in the morning is a potent strategy to counteract the decrease in anaerobic performances without affecting inflammatory response compared to the evening training.

Effect of partial sleep deprivation and racial variation on short-term maximal performance

The present study examined the effect of partial sleep deprivation (PSD) and racial variation on muscle power and fatigue during a 30-s Wingate test. In randomized order, 36 healthy football players – 12 black Tunisians (BT), 12 white Tunisians (WT) and 12 South Africans (SA) were asked to perform a 30-s Wingate test during which the peak (PP) and mean (MP) powers and the fatigue index (FI) were assessed. Measurements were performed in the afternoon after two nocturnal regimens: (i) a reference normal sleep night (RN) and (ii) 4-h of PSD caused by an early awakening (bed time: from 22:30 to 03:00 h). Our results showed that PP and MP were higher in SA than WT and BT during the RN control. Likewise, compared to this control, PP and MP were affected by PSD during the following afternoon in SA. There was a significantly greater decrease in PP and MP (p < 0.001) after the PSD in SA group compared with BT (p < 0.05) and WT (p < 0.05), values for SA, WT and BT now no longer being significantly different. However, no major difference was observed between WT and BT in regards to all parameters. Also, FI was unaffected by either sleep deprivation or racial variation. In conclusion, our results show that 4-h of PSD at the end of the night affect performance during the Wingate test at 18:00 h more in SA than Tunisians. These results suggest a greater vulnerability of SA to sleep deprivation. These results may help to guide athletes and contribute to public health recommendations for competitive events between different athletes of different ethnicity.

The effect of air pollution on diurnal variation of performance in anaerobic tests, cardiovascular and hematological parameters, and blood gases on soccer players following the Yo–Yo Intermittent Recovery Test Level-1

ABSTRACT This study aimed to investigate the effect of air pollution on diurnal variation of performance in anaerobic tests, cardiovascular and hematological parameters, and blood gases on soccer players following the Yo–Yo Intermittent Recovery Test Level-1 (YYIRT1). In a randomized order, 11 healthy soccer players (mean age: 21.8 [range: 20–24] years; height: 178.00 [range: 1.64–1.83] cm; body mass index [BMI]: 23.57 [range: 20.45–28.03] kg.m−2) performed a YYIRT1 at two different times of day (TOD) (08:00 h and 18:00 h) in two areas (i.e. polluted (PA) and non-polluted (NPA)) with a recovery period of ≥ 72 h in between, to determine the maximal oxygen uptake (VO2max). In each test session: resting oral temperature is measured, anaerobic performances (pre- and post-YYIRT1) were performed, cardiovascular parameters and blood samples were collected at: rest, 3 min and 60 min after the YYIRT1, to assess blood gases and hematological parameters. Our results showed that, agility performance, VO2max, red blood cells (RBC), hemoglobin (Hb), pH, and bicarbonate levels (HCO3−) decrease significantly (p < 0.001) following the YYIRT1 in PA compared to NPA. Likewise, the heart rate (HR), systolic blood pressure (SBP), platelets (PLT), white blood cells (WBC), neutrophiles (NEUT), lymphocytes (LYM), and partial pressure of CO2 levels (PvCO2) were significantly higher (p < 0.001) in PA. This effect was slightly accentuated at 18:00 h for some parameters (i.e. Agility, HCO3−, HR, PvCO2, RBC, SBP). However, performances of sprint and Sargent jump test (SJT), oral temperature, rate of perceived exertion scales (RPE), partial pressure of O2 (PvO2), diastolic blood pressure (DBP), and monocytes (MON) were not affected by pollution (p > 0.05). In conclusion, pollution seems to be critical for health stability and performance in response to YYIRT1 especially in the evening and the winter season. Therefore, coaches and athletes should draw attention to the potential importance of land use planning in their training sessions and competitions in the morning in polluted area to minimize the risk of pollution exposure.

Opuntia ficus-indica juice supplementation: what role it plays on diurnal variation of short-term maximal exercise?

Abstract The aim of this study was to investigate the effect of natural Opuntia ficus-indica juice (OFIJ) supplementation on anaerobic performance at two times of day. Twenty-two healthy male subjects (20.91 ± 1.22; 21.00 ± 0.84 years) divided into two groups: Experimental group (EG: n = 11) and a control group (CG: n = 11) performed two tests-sessions (30-s of Wingate test (i.e. Peak power (PP), Mean power (MP)), Sargent jump test (SJT), sprint 10 m), before and after natural OFIJ supplementation at 07:00 h and 17:00 h. T-test showed that the OFIJ has a potent antioxidant capacity for capturing free radicals following the 22-diphenyl-1-picrylhydrazyl (DPPH●) test (p < 0.05). Likewise, the ANOVA revealed that anaerobic performances were significantly higher at 17:00 h compared to 07:00 h around the peak of the temperature (p < 0.05) in both EG and CG before supplementation. Moreover, OFIJ lead an improvement of performances with (+2.09% at 07:00 h vs.+9.36% 17:00 h) for PP, (+11.29% at 07:00 h vs.+11.77% 17:00 h) for MP, (+9.42% at 07:00 h vs.+7.63% 17:00 h) for SJT in EG. The RPE scores on response to the Wingate test decrease after OFIJ supplementation (p < 0.01). For the sprint values, a significant improvement was after OFIJ (−7.10% at 07:00 h vs. −6.45% 17:00 h). However, no change was observed for CG after supplementation. In conclusion, the natural OFIJ supplementation for two weeks appears to ameliorate the performance upon two times of day with great improvement observed in the evening during short-term maximal exercise given the higher muscle damage, inflammatory, and oxidative responses at this time of day. Thus, it’s necessary that athletes, coaches, and medical staff consider the positive effects of Opuntia ficus-indica to improve anaerobic performance.