Chirine Aouichaoui

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 Ramadan observance on maximal muscular performance of trained men.

Objective:To assess the influence of Ramadan fasting on maximal performance of moderately trained young men using various tests of muscle performance. Design:Comparison of Ramadan fasting (n = 10) versus control group (n = 10) over 3 test sessions, before Ramadan (B), at the end of the first week of Ramadan (R-1), and during the fourth week of Ramadan (R-4). Setting:At each 2-day test session, 4 tests were performed in the same order: measurement of vertical jump height (VJH) and a force–velocity test using the arms on day 1, and measurement of handgrip force (HGF), and a force-velocity test using the legs on day 2. Participants:Twenty trained men. Main Outcome Measures:Maximal power of the arms and of the legs (force–velocity testing), vertical jump performance, HGF, anthropometric data, dietary intake, hemoglobin, and hematocrit. Results:Two-way analyses of variance (group × time) showed Ramadan fasters with decreased maximal anaerobic power of the arms (Wmax-A) and legs (Wmax-L) at R-1, with a partial return of arm data to initial values at R-4. Vertical jump height and HGF remained unchanged throughout. Other changes in Ramadan observers were a decreased energy intake and a decrease of plasma volume at R-1. Conclusions:These results suggest that Ramadan observance initially had detrimental effects on Wmax-A, and Wmax-L, with a tendency to recovery by week 4 of Ramadan. Reductions of total energy intake and intramuscular glycogen may contribute to the reduced Wmax-A and Wmax-L during Ramadan fasting.

The relative contributions of anthropometric variables to vertical jumping ability and leg power in Tunisian children.

Aouichaoui, C, Trabelsi, Y, Bouhlel, E, Tabka, Z, Dogui, M, Richalet, JP, and Bouchez Buvry, A. The relative contributions of anthropometric variables to vertical jumping ability and leg power in Tunisian children. J Strength Cond Res 26(3): 777–788, 2012—The purpose of this study was to examine the relative contributions of anthropometric variables to vertical jumping ability and leg power and to establish reference values of vertical jumping parameters in athletic Tunisian children aged 7–13 years in both sexes. Three hundred and ninety-one athletic Tunisian children (208 boys and 183 girls) aged 7–13 years were randomly selected to participate in our study. They were asked to perform squat jumps and countermovement jumps. Jump heights and leg power were simultaneously provided by the optojump device. Full and stepwise regression models were calculated to identify which anthropometric parameters significantly contributed to performance variables. The multiple regressions showed that age, weight, standing height and fat-free mass were the predictors of jumping performance. The results may help in verifying the effectiveness of a specific training program and detecting highly talented athletes.

Effect of rehabilitation program on endocrinological parameters in patients with COPD and in healthy subjects.

Abstract Background: Skeletal muscle wasting commonly occurs in patients with chronic obstructive pulmonary disease (COPD) and has been associated with the presence of systemic inflammation and endocrinological disturbance. The aim of this study is to analyze the effect of rehabilitation program on the balance of anabolic versus catabolic hormone in patients with COPD and in healthy subjects. Methods: Nineteen patients with COPD and 16 age-matched healthy subjects undertooked exercise training 3 days/week for 8 weeks. Before and after the training program the concentration of growth hormone (GH), Insulin-Like Growth Factor-1 (IGF-1), Insulin-like Growth Factor-Binding Protein 3 (IGF-BP3), testosterone and cortisol in serum were determined. The exercise measurements included a 6-Minute Walking Test (6MWT). Results: After 8 weeks, there was no significant change in lung function in patients with COPD and healthy subjects. Growth hormone, Insulin-like Growth Factor-1 and Insulin-like Growth Factor-Binding Protein 3 increased significantly after rehabilitation training (p < 0.01). The rehabilitation program improves the testosterone/cortisol ratio (T/C ratio) in both groups. There is a significant improvement in the 6-Minute Walking distance (6MWD) in both groups (p < 0.01). Dyspnea and heart rate at rest and at the peak of the 6-Minute Walking Test (6MWT) decreased significantly after training program (p < 0.01). Conclusion: Pulmonary rehabilitation induces an improvement of the anabolic process and reduces proteine distruction by the modifications in endocrinological factors regulating skeletal muscle in patients with COPD.

Reference values of vertical jumping performances in healthy Tunisian adolescent

Abstract Background: The assessment of normal values of muscle strength can be determined for the health outcome of adolescents, especially those who are living in a developing country. Aims: The purpose of this study is to identify the relationship between anthropometric variables and vertical jumping performances. The jump height and the average of power were measured to establish reference values of vertical jumping parameters in Tunisian healthy adolescents aged 13–19 in both sexes. Subjects and methods: Five hundred and twenty-five school adolescents (242 males and 283 females) were randomly selected to participate in this study. Maximum height and average of power reached in countermovement jump and squat jump were provided by an Optojump device. Full and stepwise regression models were used to identify which anthropometric parameters significantly contributed to performance variables. Results: All anthropometric parameters increased with age. Reference values and multiple prediction equations of vertical jump parameters were set based on a large sample of healthy Tunisian adolescents. The multiple regressions showed that age, mass, sitting height, waist size, fat-free mass and leg muscle volume for boys and mass for girls were the best predictors of jumping performances. Conclusion: This study provides normative data for jumping performances in Tunisian healthy adolescents aged 13–19 in both sexes. The percentiles values are calculated to estimate the levels of adolescents with high or low jumping performances.

Comparative Study of Bronchial Hyperresponsiveness Between Football and Judo Groups in Prepubertal Boys

Background: Exercise induced bronchospasm (EIB) commonly occurs during exercise. The comparative effects of different sports on airway responsiveness among prepubertal boys remain to be determined. Objectives: To assess differences in post exercise spirometry between footballers, judokas and a control group in prepubertal boys. Patients and Methods: A total of ninety six prepubertal boys were studied. Bronchial hyper responsiveness (BHR) to exercise challenge test was defined by a diagnosis of baseline spirometry, followed by an incremental exercise test. To date, the best test to confirm EIB may simply be standard pulmonary function testing before and after high-intensity exercise. A 10% or greater post-challenge fall in forced expiratory volume in FEV1 is used as a diagnostic criterion. Results: There was no significant difference in baseline spirometry between all groups (P > 0.05). The post exercise spirometry test revealed the presence of EIB in 16 of 32 (50%) footballers against 9 out of 32 (28.12%) in both judokas and control subjects at 5 min after the exercise. Also, there was a significantly higher decrease (P < 0.05) in mean FEV1 at 5 minuts in footballers (-9.60 ± 6.18) compared to judokas (-5.41 ± 5.85). Conclusions: The footballers have more BHR than judokas, especially at 5min after the exercise. This may be due to prolonged hyperventilation, atopy and increased exposure to inhaled allergens and pollutants during training and competition.