The purpose of this study was to investigate the diurnal variation in some specific skills performance during field testing in boy's footballer. In a balanced and randomized study design, 15 boys (mean ± SD; age 12.7 ± 1.1 years; height 1.54 ± 9.1 m; body mass 45.1 ± 3.2 kg) participated in the study. Subjects performed some specific soccer skills (kicking accuracy, ball control with the body, ball control with the head, coordination test, zigzag running (i.e., agility), zigzag with the Ball (i.e., dribbling) and the skill index (i.e., the ratio of the zigzag running without and with the ball) at two different times of day: 07:00 and 17:00 h. Moreover, intra-aural temperature was measured at both time-of-days. Intra-aural temperature was higher in the evening than the morning (P < 0.01). Likewise, a significant time-of-day effect was found for dribbling (P < 0.05) and agility (P < 0.001) with higher performances observed at 17:00 h. However, no significant differences were noticed between 07:00 and 17:00 h for the skill index, kicking accuracy, ball control with the body, ball control with the head and coordination tests. The intra-aural temperature was found to be significantly correlated with the speed of dribbling and agility (P < 0.001). In conclusion, a diurnal variation in intra-aural temperature, agility and dribbling were shown to be present. No time-of-day effect was observed for the coordination, skill index, kicking accuracy and juggling performance.

Background This study addressed the lack of data on the effect of warm-up (WU) duration in hot-dry climate (~ 30 °C; ~ 18% RH), on thermoregulation, muscular power-output, and fatigue after specific soccer repeated-sprint test (RSA). Methods Eleven amateur soccer players participated in a cross-over randomized study and they underwent the Bangsbo repeated-sprint test, after three WU durations (i.e. WU10, WU15 and WU20 min) at 70% of MAV, and on different days. Peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analyzed. Likewise, heart rate (HR), tympanic temperature (Ttym), mean body temperature (MBT) and rating of perceived exertion (RPE) were recorded during each session. Results The repeated measure ANOVA showed that MP improved after WU15 in comparison to WU10 and WU20 (p = 0.04 and p = 0.001; respectively). Nonetheless, no significant effect on PP was recorded after all WU durations. FI during RSA increased after WU20 in comparison to WU15 and WU10 (p < 0.001 and p = 0.003; respectively). Higher RPE values (p < 0.001) were recorded after WU15 and WU20 in comparison to WU10 duration. The two-way ANOVA showed higher ΔTtym and ΔMBT values after WU15 and WU20 compared to WU10 (p = 0.039 and p < 0.001for Ttym; p = 0.005 and p < 0.001 for MBT, respectively). Conclusions The WU15 at 70% of MAV better assists mean power-output during soccer RSA in hot-dry (~ 30 °C; 18% RH) climate, but not peak power. Reducing WU duration up to 10 min seems to be insufficient to induce beneficial physiological changes necessary for optimizing repeated-sprint performance, while its extension up to 20 min remains detrimental for muscular power and induces higher fatigue.

This study will evaluate cardiorespiratory and peripheral muscle function and their relationship with subjective dyspnea threshold after the surgical correction of congenital heart disease in children. Thirteen children with surgically repaired congenital heart disease were recruited. Each participant performed an incremental exercise test on a cycle ergometer until exhaustion. Gas exchanges were continuously sampled to measure the maximal aerobic parameters and ventilatory thresholds. The functional capacity of the subjects was assessed with a 6 min walk test. At the end of the exercise test, isokinetic Cybex Norm was used to evaluate the strength and endurance of the knee extensor muscle in the leg. Dyspnea was subjectively scored with a visual analog scale during the last 15 s of each exercise step. Oxygen consumption measured at the dyspnea score/VO2 relationship located at the dyspnea threshold, at which dyspnea suddenly increased. Results: The maximal and submaximal values of the parameters describing the exercise and the peripheral muscular performances were: VO2 Peak: 33.8 ± 8.9 mL·min−1·kg−1; HR: 174 ± 9 b·min−1; VEmax: 65.68 ± 15.9 L·min−1; P max: 117 ± 27 W; maximal voluntary isometric force MVIF: 120.8 ± 41.9 N/m; and time to exhaustion Tlim: 53 ± 21 s. Oxygen consumption measured at the dyspnea threshold was related to VO2 Peak (R2 = 0.74; p < 0.01), Tlim (R2 = 0.78; p < 0.01), and the distance achieved during the 6MWT (R2 = 0.57; p < 0.05). Compared to the theoretical maximal values for the power output, VO2, and HR, the surgical correction did not repair the exercise performance. After the surgical correction of congenital heart disease, exercise performance was impeded by alterations of the cardiorespiratory function and peripheral local factors. A subjective evaluation of the dyspnea threshold is a reliable criterion that allows the prediction of exercise capacity in subjects suffering from congenital heart disease.

Background Physical education teachers often experience stress and job disengagement. Objective This study’s aims were as follows: (1) to adapt in the Arabic language and test the reliability and the validity of the work–family conflict (WFC) and family–work conflict (FWC) scales, (2) to develop and assess the psychometric properties of work disengagement among physical education teachers, and (3) to evaluate an explanatory model by presenting the mediating role of perceived stress as a major influencing factor in work disengagement and job satisfaction. Methods A total of 303 primary and secondary school physical education teachers, comprising 165 (54.5%) men and 138 (45.5%) women participated voluntarily in our study. The measuring instruments are the Work Disengagement Scale, the Perceived Stress Scale, the WFC scale, the FWC scale, and the 9-item Teacher of Physical Education Job Satisfaction Inventory. Results The Arabic language versions of the WFC and FWC scales had reasonably adequate psychometric properties, which were justified by confirmatory factor analyses and by the measurement of reliability, convergent, and discriminant validity through the measurement model using SmartPLS software. Similarly, the structural model established with SmartPLS confirmed strong links of the concepts of FWC, WFC, the job satisfaction questionnaire, and perceived stress with work disengagement among teachers of physical education. Conclusions There is a growing interest in helping teachers cope with the daily pressures of work and family. A positive organizational context is a context with clear values regarding work priorities, which constitutes the basis of a feeling of shared responsibility and professional support. Good conditions can act as protective factors reducing work stress and positively influencing personal well-being, work attitudes, work commitment, and professional efficiency. Additional research on teachers is needed to examine the relationship between perceived work stress and the role of families, along with the extent to which this association can have a significant impact on teachers’ commitment to work.

BACKGROUND Physical education teachers often experience stress and job disengagement. OBJECTIVE This study aims to develop a measurement scale of job disengagement among physical education teachers and to present an explanatory model by presenting the mediating role of perceived stress as a major factor in disengagement and job satisfaction, also the relationship between family and work as an indirect effect for this phenomenon. METHODS A total of 268 primary and secondary school physical education teachers, made up of 165 men (54.46%) and 138 women (45.54%) participated voluntarily in our study. The measuring instruments are the work disengagement scale, the Perceived stress scale, the Work-family conflict scale (WFC), the family-work conflict scale (FWC), and the scale of dissatisfaction at work. RESULTS the Arabic language versions of the WFC and the FWC had reasonably adequate psychometric properties which were justified by confirmatory analyzes and by the measurement of reliability, convergent and discriminant validity through the measurement model in SmartPls. Likewise, the structural model established with the SmartPLS software confirmed strong links of the concepts FWC, WFCS, the questionnaire of job satisfaction, the perceived stress with the disengagement of work among teachers of physical education. CONCLUSIONS There is a growing interest in helping teachers cope with the daily pressures of work and family. A positive organizational context is a context with clear values regarding work priorities that constitutes the basis of a feeling of shared responsibility and professional support.Good conditions can act as protective factors reducing work stress and positively influencing personal well-being, work attitudes, work commitment, and professional efficiency. Additional teacher research is needed to examine the relationship between perceived work stress and the role of families, also the extent to which this association can have a significant impact on teachers' commitment to work.