Background: Postural balance represents a fundamental movement skill for the successful performance of everyday and sport-related activities. There is ample evidence on the effectiveness of balance training on balance performance in athletic and non-athletic population. However, less is known on potential transfer effects of other training types, such as plyometric jump training (PJT) on measures of balance. Given that PJT is a highly dynamic exercise mode with various forms of jump-landing tasks, high levels of postural control are needed to successfully perform PJT exercises. Accordingly, PJT has the potential to not only improve measures of muscle strength and power but also balance.Objective: To systematically review and synthetize evidence from randomized and non-randomized controlled trials regarding the effects of PJT on measures of balance in apparently healthy participants.Methods: Systematic literature searches were performed in the electronic databases PubMed, Web of Science, and SCOPUS. A PICOS approach was applied to define inclusion criteria, (i) apparently healthy participants, with no restrictions on their fitness level, sex, or age, (ii) a PJT program, (iii) active controls (any sport-related activity) or specific active controls (a specific exercise type such as balance training), (iv) assessment of dynamic, static balance pre- and post-PJT, (v) randomized controlled trials and controlled trials. The methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. This meta-analysis was computed using the inverse variance random-effects model. The significance level was set at p <0.05.Results: The initial search retrieved 8,251 plus 23 records identified through other sources. Forty-two articles met our inclusion criteria for qualitative and 38 for quantitative analysis (1,806 participants [990 males, 816 females], age range 9–63 years). PJT interventions lasted between 4 and 36 weeks. The median PEDro score was 6 and no study had low methodological quality (≤3). The analysis revealed significant small effects of PJT on overall (dynamic and static) balance (ES = 0.46; 95% CI = 0.32–0.61; p < 0.001), dynamic (e.g., Y-balance test) balance (ES = 0.50; 95% CI = 0.30–0.71; p < 0.001), and static (e.g., flamingo balance test) balance (ES = 0.49; 95% CI = 0.31–0.67; p < 0.001). The moderator analyses revealed that sex and/or age did not moderate balance performance outcomes. When PJT was compared to specific active controls (i.e., participants undergoing balance training, whole body vibration training, resistance training), both PJT and alternative training methods showed similar effects on overall (dynamic and static) balance (p = 0.534). Specifically, when PJT was compared to balance training, both training types showed similar effects on overall (dynamic and static) balance (p = 0.514).Conclusion: Compared to active controls, PJT showed small effects on overall balance, dynamic and static balance. Additionally, PJT produced similar balance improvements compared to other training types (i.e., balance training). Although PJT is widely used in athletic and recreational sport settings to improve athletes' physical fitness (e.g., jumping; sprinting), our systematic review with meta-analysis is novel in as much as it indicates that PJT also improves balance performance. The observed PJT-related balance enhancements were irrespective of sex and participants' age. Therefore, PJT appears to be an adequate training regime to improve balance in both, athletic and recreational settings.

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The aim of this systematic review with meta-analysis was to assess the available body of published peerreviewed articles related on the effects of jump rope training (JRT) compared with active/passive controls on health-and sport-related physical fitness outcomes. Searches were conducted in three databases, including studies that satisfied the following criteria: i) healthy participants; ii) a JRT program; iii) active or traditional control group; iv) at least one measure related to health-and sport-related physical fitness; v) multi-arm trials. The random-effects model was used for the meta-analyses. Twenty-one fair-good quality (i.e., PEDro scale) studies were meta-analysed, involving 1,021 participants (male, 50.4%).Eighteen studies included participants with a mean age <18 years old. The duration of the JRT interventions ranged from 6-40 weeks. Meta-analyses revealed improvements (i.e., p= 0.048 to <0.001; ES= 0.23-1.19; I 2 = 0.0-76.9%) in resting heart rate, body mass index, fat mass, cardiorespiratory endurance, lower-and upper-body maximal strength, jumping, range of motion, and sprinting. No significant JRT effects were noted for systolic-diastolic blood pressure, waist-hip circumference, bone or lean mass, or muscle endurance. In conclusion, JRT, when compared to active and passive controls, provides a range of small-moderate benefits that span health-and sport-related physical fitness outcomes.

Sprinting ability is of paramount importance for successful performance in sports. The main aim of this study was to examine the correlation between force-velocity-power relationship of a whole-body movement and sprint performance (20 and 60 m sprint time (t20 and t60) and maximum sprint velocity (Vmax). Twelve male participants performed maximal squat jumps with additional loads ranging from 0 to 100 % body weight to obtain force-velocity profiles. The mean force and velocity were calculated during the push-off phase for each jump, which resulted in a force-velocity curve. The theoretical maximal force (F0), theoretical maximal velocity (V0) and theoretical maximum power (P0) were computed via extrapolation of the force and velocity data. In the second session, participants performed two 60 m sprints and the time to cover t 20 , t 60 and Vmax were calculated from the best 60 m trial. Correlation analyses revealed strong a n d s i g n i f i c a n t correlations between V 0 and t20 (r =-0.60), V0 and t60 (r =-0.60), P 0 and t20 (r =-0.75), P0 and t60 (r =-0.78). M ultiple linear regression indicated that P 0 explained 56%, 61%, 60% of the variability in t20, t60 and Vmax respectively. Our results emphasize the importance of developing power production capabilities to improve sprint performance.

Background: The main aim of this study was to evaluate the relationships between training workload (WL) parameters with variations in the change of direction (COD) in under-16 soccer players. Methods: Twenty-seven under-16 elite soccer players were daily monitored for their WL across 15 weeks during the competitive soccer season. Additionally, players were assessed two times for anthropometric measures (weight, height, sitting height and leg length), COD performance (modified 505 test) and maturity offset measured using the peak height velocity (PHV). Results: A correlational analysis was performed to determine the relationship between the variation in COD performance and accumulated WL parameters. Moreover, a regression analysis was executed to explain the variations in the percentage of COD performance considering the accumulated WL parameters and PHV of the season (r = 0.93; p ≤ 0.01) and training monotony during the early-season (r = 0.53; p ≤ 0.05). There were associations between the acute workload during the start of the season and the COD during the end of the season (r = 0.47; p ≤ 0.05). The multiple linear regression analysis showed that 55% of the variation in COD performance between the early and end of season could be explained by the acute or chronic WL, training monotony or strain and the PHV. Conclusions: This information might be useful for practitioners and coaches aiming to improve the COD performance in youth soccer players during an entire competitive season.