This study examined the effects of 8 weeks of twice-weekly combined plyometric and sprint with change-of-direction (CPSCoD) training into habitual training regimes of young male soccer players. Participants were randomly allocated to an experimental group (n = 17, age: 14.6 ± 0.44 years, body mass: 61.2 ± 7.34 kg, height: 1.67 ± 0.09 m, body fat: 11.2 ± 1.56%) and a control group (n = 16, age: 14.6 ± 0.39 years, body mass: 61.1 ± 3.96 kg, height: 1.67 ± 0.05 m, body fat: 11.8 ± 1.47%). Measures obtained pre- and post intervention included vertical and horizontal jump performance (i.e., squat jump (SJ), countermovement jump (CMJ), and standing long jump (SLJ)), and sprint performance (i.e., 5 m and 20 m sprint). In addition, Measures obtained pre- and post-intervention included change-of-direction ability (4 × 5 m sprint test (S 4 × 5 m) and sprint 9–3–6–3–9 m with backward and forward running (SBF)), repeated change of direction (RCoD), and static balance performance (stork balance test). The training group experienced superior jump (all p < 0.05; d ≥ 0.61), sprint (all p < 0.05; d ≥ 0.58), change-of-direction (CoD) ability (all p < 0.05; d ≥ 0.58), RCoD (all parameters except the fatigue index p < 0.01; effect size (d) ≥ 0.71), and static balance (all p < 0.05; d ≥ 0.66) improvement. Adding twice-weekly CPSCoD training to standard training improves the anaerobic performance of U15 male soccer players.

Exploring resistance training methods is crucial for optimizing performance programs. Isometric muscle actions have gained popularity in athletic training, but their impact on dynamic performance is uncertain. Isolated isometric actions also lack ecological validity. We compared the effects of 8-week combined isometric and plyometric (COMB) training and contrast strength training (CST) programs on junior male handball players. Thirty-six male first national division players (17.6 ± 1.0 years) were enrolled and randomly assigned to COMB, CST, or control (CONT) groups (all n = 12). Sprinting, change of direction, ball throwing velocity, jumping, and strength were assessed pre- and post-intervention. A significant group × time interaction was observed between the COMB and CONT groups for 20 and 30 m sprints (p ≤ 0.002) and between the COMB and CST groups (p ≤ 0.042). The COMB group had the largest improvements in change of direction and the modified T-test, with significant group × time interactions between the COMB and CONT groups (p ≤ 0.021). Significant group × time interactions were observed between the COMB and CST groups and between the COMB and CONT groups for 3 step running throw (p = 0.003; p < 0.001), running throw (p = 0.02; p = 0.031), and jumping throw (p = 0.001; p < 0.001). Countermovement jump showed a significant group × time interaction (p = 0.014), with the COMB group outperforming the other groups. Generally, COMB yielded larger improvements than CST. Coaches should consider incorporating a combination of isometric and plyometric exercises for in-season strength training.

The purpose of this study was to investigate the relationship between mental fatigue induced by a demanding cognitive task and impaired physical performance in endurance due to a higher perception of effort. A total of 12 healthy adults and volunteers, who had previously practiced endurance activities for 4 to 8 h per week, performed a one-hour cognitive task involving either the process of response inhibition (Stroop task) or not (visualization of a documentary as control task), then 20 min of pedaling on a cycle ergometer at a constant perception of effort while cardio-respiratory and neuromuscular functions were measured. The Stroop task induces subjective feelings of mental fatigue (vigor: 3.92 ± 2.61; subjective workload: 58.61 ± 14.57) compared to the control task (vigor: 5.67 ± 3.26; p = 0.04; subjective workload: 32.5 ± 10.1; p = 0.005). This fatigue did not act on the produced perceived effort, self-imposed, and did not affect the cardio-respiratory or neuromuscular functions during the subsequent physical task whose type was medium-term endurance. Regardless of the mental condition, the intensity of physical effort is better controlled when the participants in physical activity control their perception of effort. Mental fatigue does not affect subsequent physical performance but estimated perceived exertion, which increases with the intensity and duration of the exercise.

The objective of the study was the translation and adaptation into Arabic language of the Questionnaire on Teacher Interaction and the examination of psychometric properties among students in Tunisia. A set of students (N = 778) were recruited to complete a translated, Arabic version of the Teacher Interaction Questionnaire (AQTI). The subjects represented both female and male with an average age of 15.98 ± 2.17 years. The subjects were divided into exploratory (N = 226) and confirmatory (N = 552) samples. For the exploratory sample, the female sex represented 46.90% and the male 53.10% (N = 120). Likewise, the confirmatory sample consisted of females (48.01%) and males (51.99%). The scale designed in Arabic AQTI presented eight components for exploratory factor analysis. The result was a first factorial solution, which kept these eight components of the predetermined instrument. The confirmatory factor analysis provided good fit indices. Similar results for instrument reliability were confirmed for all dimensions, through good Cronbach’s coefficient, which were superior to 0.80. The Arabic version of AQTI is valid and reliable and can be administered to assess teacher/student interactions in Tunisia. However, further research needs to examine the construct validity of the instrument.

Aim: This study analyzed the concurrent validity of the Optojump infrared photocell system for estimating lower limb peak power by comparing it with the 15 s Wingate anaerobic test (WAnT) and examining relationships with sprint performance indicators. Methods: Twelve physically active university students (ten males, two females; age: 23.39 ± 1.47 years; body mass: 73.08 ± 9.19 kg; height: 173.67 ± 6.97 cm; BMI: 24.17 ± 1.48 kg·m⁻²) completed a cross-sectional validation protocol. Participants performed WAnT on a calibrated Monark ergometer (7.5% body weight for males, 5.5% for females), 30 s continuous jump tests using the Optojump system (Microgate, Italy), and 30 m sprint assessments with 10 m and 20 m split times. Peak power was expressed in absolute (W), relative (W·kg⁻¹), and allometric (W·kg^−0.67) terms. Results: Thirty-second continuous jump testing produced systematically higher peak power values across all metrics (p < 0.001). Mean differences indicated large effect sizes: relative power (Cohen’s d = 0.99; 18.263 ± 4.243 vs. 10.99 ± 1.58 W·kg⁻¹), absolute power (d = 0.86; 1381.71 ± 393.44 vs. 807.28 ± 175.45 W), and allometric power (d = 0.79). Strong correlations emerged between protocols, with absolute power showing the strongest association (r = 0.842, p < 0.001). Linear regression analysis revealed that 30 s continuous jump-derived measurements explained 71% of the variance in Wingate outcomes (R² = 0.710, p < 0.001). Sprint performance showed equivalent predictive capacity for both tests (Wingate: R² = 0.66; 30 s continuous jump: R² = 0.67). Conclusions: The Optojump infrared photocell system provides a valid and practical alternative to laboratory-based ergometry for assessing lower limb anaerobic power. While it systematically overestimates absolute values compared with the Wingate anaerobic test, its strong concurrent validity (r > 0.80), large effect sizes, and equivalent predictive ability for sprint performance (R² = 0.66–0.71) confirm its reliability as a field-based assessment tool. These findings underscore the importance of sport-specific, weight-bearing assessment technologies in modern sports biomechanics, providing coaches, practitioners, and clinicians with a feasible method for monitoring performance, talent identification, and training optimization. The results further suggest that Optojump-based protocols can bridge the gap between laboratory precision and ecological validity, supporting both athletic performance enhancement and injury prevention strategies.

The purpose of the study was to evaluate the reproducibility of the medicine ball explosive power test to assess explosive power in young volleyball players. Materials and methods. Data were collected using twelve volleyball players (age = 16.5 ± 0.52 years; body mass = 72.05 ± 7.9 kg; height = 182 ± 0.06 cm and body mass index = 21.63 ± 1.85) volunteered for this study. They completed a test and retest of the medicine ball explosive power test on two separate days. The medicine ball explosive power test was conducted using a 3 kg medicine ball. Testing was carried out in two separated testing session preceded by a standardized warming up protocol. The paired-sample t-test was conducted to determine the differences signification observed between the test and the retest of the medicine-ball explosive power test. The intraclass correlation coefficient (ICC1,1) aims to assess relative reliability of the test. The coefficient of variation between test and retest performance was used to check the absolute reproducibility. The Bland and Altman method was used to evaluate the relative and absolute reproducibility of the medicine ball explosive power test. Results and discussion. Explosive power is often considered as one of the main determinants of a successful high-level performance in many team sports including volleyball. It is frequently measured in different occasion during competitive season using field‐based tests. Thus, it is mandatory that strength and conditioning coaches have to use valid and reliable tests to evaluate the power for their athletes. However, contestation regarding test selection still exists grounded upon the particularity of the explosive power evaluation tests in volleyball. There was no significant difference between medicine ball explosive power test (11.08 ± 0.72 meter) and retest (11.27 ± 0.93 meter) performance. The T-paired Sample test did not show any statistically significant difference (t= 1.035; p =0.393), while the intraclass correlation coefficient aimed to assess relative reliability of the test was of 0.83. The coefficient of variation between test and retest performance was of 5.7% which is near to the 5% confidence interval level. The intraclass correlation coefficient was situated between 0.9 and 0.8 (ICC1,1 = 0.83) Thus this study suggests that the medicine ball explosive power test has moderate relative reliability level. Conclusion. The medicine ball explosive power test is reliable regardless to the age. The Bland and Altman method confirmed our finding suggesting the medicine ball explosive power test is a reliable test