This study examines the effects of two plyometric training interventions over an eight-week preparatory period on straight punch impact force, cardiovascular fitness, and muscle strength in national-level boxers. Twenty male professional boxers participated voluntarily, with an average age of 22.64 ± 3.12 years and an average training experience of 5.11 ± 0.88 years. Their mean body weight and height were 70.20 ± 10.13 kg and 184.28 ± 5.38 cm, respectively. The participants were randomly assigned to two groups. Group 1, the Plyometric Stair Jump group, consisted of ten male boxers, while Group 2, the Plyometric Reaction Box Jump group, also included ten male boxers. To assess maximum punching velocity (PVmax), an accelerometer was embedded within the boxing glove, capturing data during three maximal-speed jabs with each arm to evaluate both rear-arm (RA) and lead-arm (LA) punches. Upper-body strength was assessed using a one-repetition maximum (1RM) bench press (BP) test, while maximum velocity at various percentages of 1RM was recorded via a linear encoder. Significant correlations were observed between the right arm punch velocity maximum (RA PVmax) and the bench press velocity at all submaximal intensities in both intervention groups (p < 0.05). However, no correlation was found between left arm punch velocity maximum (LA PVmax) and bench press velocity at any intensity within the Plyometric Reaction Jump (PRJ) group. Conversely, in the Plyometric Stair Jump (PSJ) group, a velocity at 80% of 1RM was the sole significant predictor of RA PVmax at submaximal bench press intensities. Adjusting for the strength-to-weight ratio significantly influenced the predictive values in intergroup comparisons (p < 0.005). These findings suggest that high-load bench press exercises (e.g., at 80% 1RM) may serve as reliable predictors of performance in specific boxing movements. However, since no significant relationship was observed with LA PVmax in this study, further research is warranted to identify exercises and intensities that may explain left arm punch velocity.

Handball requires athletes to sustain intermittent high-intensity effort while maintaining rapid cognitive processing and technical skills. Caffeine is widely used as an ergogenic aid, yet its dose-dependent effects across physical, cognitive, and technical performance outcomes remain unclear in female handball players. This randomized, double-blind, placebo-controlled crossover study examined the acute effects of low-dose caffeine (LCAF; 3 mg/kg), moderate-dose caffeine (MCAF; 6 mg/kg), and placebo (PLA) in trained female handball players. Participants (n = 20) completed three experimental sessions separated by 72 h. Cognitive performance was assessed using the Simplified Eriksen Flanker Test, throwing performance was evaluated through maximal ball velocity, and intermittent running capacity was measured with the Yo-Yo Intermittent Recovery Test Level 1. Both LCAF and MCAF significantly improved Yo-Yo performance compared with PLA (η²p = 0.415, representing improvements of approximately ~23.5% and 29.0%), with no difference between caffeine doses. MCAF significantly reduced overall Flanker response time (η²p = 0.486, ~18.5%) and congruent and incongruent trial response time compared with PLA and LCAF. No significant effects were observed for throwing velocity, Flanker accuracy and interference scores. These findings suggest that acute caffeine intake has performance-specific effects in female handball players: intermittent running performance responded to both doses, whereas cognitive enhancement was limited to response time, with no improvements in inhibitory control or accuracy.

Background: Relationships between heart rate and running velocity at fixed blood lactate concentrations with short-duration performance remain uncertain in U19 soccer players. This exploratory cross-sectional study examined their associations with 10 m sprint time and countermovement jump (CMJ) height. Methods: Sixteen male players from a U19 development squad completed CMJ and 10 m sprint assessments followed by an incremental field-running test. The best result from two CMJ and two sprint trials was analyzed. Pearson correlations were reported with 95% confidence intervals, and the Benjamini–Hochberg procedure controlled the false discovery rate (FDR) across 24 tests. Results: Nominal positive correlations were observed between 10-m sprint time and heart rate at fixed blood lactate concentrations of 2.0–3.5 mmol·L⁻¹ (r = 0.503–0.579; raw p = 0.019–0.047), indicating that higher heart rate was associated with longer sprint time. None remained statistically significant after FDR correction (q ≥ 0.207). No CMJ or running-velocity association survived FDR correction. Conclusions: The data did not provide multiplicity-corrected evidence of associations between fixed-concentration test responses and sprint or jump performance. The estimates are exploratory and require confirmation in larger, prospectively powered samples.

Objectives: The aim of this study was to conduct a comprehensive, holistic examination, using meta-analysis, of the effects of core stabilisation training on speed and jumping-key indicators of athletic performance-in individuals participating in various sports. Methods: Studies published in Web of Science, PubMed and Google Scholar between 2020 and June 2026 examining speed and jumping performance were screened. Studies involving pre-test–post-test designs with experimental and control groups were recorded for analysis. A total of 49 studies meeting the inclusion criteria were included. This meta-analysis followed the PRISMA statement reporting guidelines. The CMA Ver. 2.0 statistical package was used to assess publication bias, calculate means and standard deviations, determine effect sizes and perform moderator analyses. The I² statistic assessed heterogeneity between studies; 25 per cent, 50 per cent and 75 per cent cut-off values represent low, moderate and high levels, respectively. Due to anticipated clinical and methodological diversity across sports disciplines, participant competitive levels, and test protocols, a random-effects model was applied a priori for all pooled analyses across speed and jumping outcomes. All estimates are reported with corresponding 95 per cent confidence intervals (CI). The α level was set at 0.05 for statistical significance. Results: The findings of this meta-analysis, which included a total of 49 studies, indicate that core training has a positive effect on the speed and jumping performance of individuals participating in various sports. The overall effect size calculated for speed performance was 0.601, whilst the overall effect size for jumping performance was determined to be 0.489. These findings indicate that core training has a positive effect on both speed and jumping performance. Conclusions: Core training is a useful complementary method for improving speed and jumping performance. Its effectiveness depends not only on training duration and sample size but also on exercise selection, intensity, frequency, athlete characteristics, and sport specificity. Therefore, combining core training with sport-specific sprint, strength, and plyometric exercises may enhance athletic performance.