Prolonged submaximal exercise induces reductions in vascular conductance to splanchnic and renal circulations. We aimed to evaluate in the present study the effect of melatonin on the renal response to submaximal exercise. Eight students aged between 20-23 years participated in the study. They ran at 60% of their maximal aerobic speed (MAS) for 45min after 50min of either melatonin-(6mg) or placebo ingestion, in a randomized order. The rectal temperature (Tre) and heart rate (HR) were measured. Felt arousal scale was measured at the beginning and at the end of the rest. Blood samples were taken before and after exercise, from which the hemoglobin (Hb), hematocrit (Hct), sodium (Na+), potassium (K+), bicarbonate (HCO3-), pH, urea, uric acid, creatinine, parathyroid hormone (PTH), calcium (Ca2+), chloride (Cl-), phosphor (P) and vitamin D concentrations were measured. Creatinine clearance was calculated based on the Cockcroft-Gault equation. Hb and Hct increased after exercise only in the placebo condition. Our results showed that Tre increased significantly at the end of exercise in both conditions (P < 0.001). HR was significantly attenuated in melatonin condition at the end of the exercise (P < 0.01). There was no statistical difference in creatinine clearance between conditions, but PTH was significantly higher in melatonin condition compared to placebo (68.6 and 51.9; P = 0.01) at the end of the exercise. Our finding revealed that melatonin increases the extent of the exercise-induced increase in PTH. We suggest that melatonin induce renal vasoconstriction during prolonged exercise owing to the alteration of renal blood flow.

Background: Soccer players require a plethora of physical capabilities to compete at a higher level. It would be interesting to determine which physical attributes are required for starting players (SP, players chosen in the squad starting the games), and what sets them apart from non-starting players (NSP). Aim: 1) to compare physical attributes of SP vs. NSP, and 2) to determine if strength ratios calculated from maximal isometric strength (MIVC) is useful to differentiate between two different groupsof players. Methods: Thirty U17 right-leg dominant elite youth soccer players were divided in two groups (starters players [SP; N=15] and non-starters players [SP; N=15]. All players performed a battery of tests: 10m straight-sprint (10 m SS), change of direction (COD), maximal isometric voluntary contraction (MIVC), jumping and dynamic-balance tests. Hamstring to quadriceps ratios (H: Q) and side to side asymmetry werealso calculated from MIVC tests. Results: Comparison results showed that SP didbetter in jumping tests (five-jump test [5JT] and broad jump test[BJT] compared to NSP. SP were also able to exert more isometric strength when compared to NSP. SP were faster and presented a better COD ability than NSP. However,no significant differences between the two groups in dynamic-balance ability. Agreater H: Q asymmetry was observedamong NSP compared to SP. Conclusions: Youth elite SP’s may be distinguished from NSP’s through higher isometric strength, jumping, speed and COD tests. Thus, coaches can use theses field tests for designing specific training programs for substitute players to reach a higher level of soccer play.

The aim of this study was to investigate whether 24 sessions of velocity based training (VBT) exercise could changes the neuromuscular and functional performance in the elderly women. Six elderly participants (65 ± 5 years; 1,51 ± 0,05 m; 64 ±16 kg) were submitted to a progressive VBT regime (two sessions/week) using a squat jump barbell exercise. Time up and go (ES 0.86, large; p=0.01), squat jump (ES 0.71, moderate; p=0,03), squat jump barbell (ES 1.37, large; p=0,03), and dynamic knee extension (ES 0.54, moderate, p=0,04) were statistical different within period (POST better than PRE). On the other hand, results isometric knee extension (ES 0.12, small, p=0,58) and dynamic knee flexion (ES 0.08, small, p=0,72) did not show changes after the experimental period. In summary, the results of this study suggested that 24 sessions of VBT exercise influenced the functional performance (TUG); squat jump height and load of the barbell squat jumps; fast concentric knee extensor (180o/s), but not the flexion concentric (180o/s) and isometric knee extensor torques in a group of elderly women.

Objectives: We aimed to adapt an instrument which is one of the most used in studies of emotions and mental evaluation, therefore we tried to verify if it is still applicable in sport domain and propose a Tunisian version pf the scale. Method: An experimental approach was used, plying the scientific research methods such as the linguistic adaptation, the factorial and statistical analysis of our data. Results: The varimax rotation with only 15 items alpha Chrombach improves .65 to .72 by removing the items (9, 10, 12, 16 and 17). Hence, the possibility of abbreviated 15 items instead of 20 was one of our goals, namely to create a new sensitive faithful and valid tool adapted to the Tunisian athlete population. Conclusion: Psychometric evaluation confirms an inter-sample stability, internal reliability, temporal stability, a transcultural factorial invariance, and the validity of the convergence criteria.

Social understanding in children with autism represents a barrier to the integration of autistic people into Arab societies and specifically Tunisian society. Considered as a handicap, autism remains a real public health problem. If the contact with the water allows a moment of playing and relaxation, the practice of regular aquatic activities can become a real asset in the daily life. The present study aims to prove that regular water activities for children with autism could improve the social understanding of autistic people and thus facilitate their social integration into Tunisian society. To do this, we used two investigative tools, namely semi-directive interviews and direct and non-participatory observation with two young autistic Tunisians, a girl and a boy. The results of the analysis of the data of the different themes (motor stability, imitation, pointing, sharing and eye contact) indicate great improvements in social understanding.

The aim of the present study was to evaluate the reciprocal style of teaching, in typical tennis strokes, such as forehand and backhand. A sample of 102 children, aged 14-15, who had no previous experience in tennis participated in this study. Students were engaged in 12 lessons held in their school environment. The experimental group was subjected to experimental intervention for 6 weeks in the independent variable which is the reciprocal teaching method for strokes, while the control group was not subjected to any intervention and was not trained following this teaching style. Data was processed by statistical analysis through t-test for independent samples. The results showed that the reciprocal style of teaching had increased the mean of consecutive strokes regardless of gender, with the experimental group showing a significant improvement in performance in the measured wall test, in comparison to the control group which showed no improvement.