Background: Plyometric training can be performed through many types of exercises involving the stretch-shortening cycle in lower limbs. In the last decades, a high number of studies have investigated the effects of plyometric training on several outcomes in different populations. Objectives: To systematically review, summarize the findings, and access the quality of published meta-analyses investigating the effects of plyometric training on physical performance. Design: Systematic umbrella review of meta-analyses. Data Sources: Meta-analyses were identified using a systematic literature search in the databases PubMed/MEDLINE, Scopus, SPORTDiscus, Web of Science, Cochrane Library and Scielo. Eligibility Criteria for Selecting Meta-analyses: Meta-analyses that examined the effects of plyometric training on physical fitness in different populations, age groups, and sex. Results: Twenty-nine meta-analyses with moderate-to-high methodological quality were included in this umbrella review. We identified a relevant weakness in the current literature, in which five meta-analyses included control group comparisons, while 24 included pre-to-post-effect sizes. Trivial-to-large effects were found considering the effects of plyometric training on physical performance for healthy individuals, medium-trivial effects for the sports athletes’ groups and medium effects for different sports athletes’ groups, age groups, and physical performance. Conclusion: The available evidence indicates that plyometric training improves most related physical fitness parameters and sports performance. However, it is important to outline that most meta-analyses included papers lacking a control condition. As such, the results should be interpreted with caution. PROSPERO number: CRD42020217918.

Male judo athletes participated in this study. The athletes performed three 5-minute judo matches separated by 15 minutes of passive rest between each match. The following measurements were performed before and after each match: shoulder external/internal rotation isokinetic torque and countermovement jump (CMJ). Blood samples were taken before the first match and after the third match for serum creatine kinase (CK) and lactate dehydrogenase (LDH) analysis. T-tests for dependent samples and analysis of variance for repeated measures were used to compare the variables over the time; the level of significance was set at 0.05. An overall effect of the successive matches on shoulder internal (PTIN) and external (PTEX) rotation peak torque and CMJ performance was observed. PTIN and PTEX showed significant decreases in postmatch 2 and postmatch 3 when compared with the baseline (p < 0.01). Also, CMJ height declined in postmatch 2 and postmatch 3 (p < 0.01) when compared with the baseline. Serum CK and LDH activity increased significantly after the third match (p < 0.01). It was concluded that 3 successive judo matches induced a decline of peak torque and muscle power in the upper and lower limbs, respectively, and also provoked an increase of muscle damage markers. These findings may provide important knowledge for coaches and physical trainers to improve judo-specific strength training in both the upper and lower limbs....

Kons, RL, Ache-Dias, J, Detanico, D, Barth, J, and Dal Pupo, J. Is vertical jump height an indicator of athletes' power output in different sports modalities? J Strength Cond Res 32(3): 708–715, 2018—This study aimed to identify whether the ratio standard is adequate for the scaling of peak power output (PPO) for body mass (BM) in athletes of different sports and to verify classification agreement for athletes involved in different sports using PPO scaled for BM and jump height (JH). One hundred and twenty-four male athletes divided into 3 different groups—combat sports, team sports, and runners—participated in this study. Participants performed the countermovement jump on a force plate. Peak power output and JH were calculated from the vertical ground reaction force. We found different allometric exponents for each modality, allowing the use of the ratio standard for team sports. For combat sports and runners, the ratio standard was not considered adequate, and therefore, a specific allometric exponent for these 2 groups was found. Significant correlations between adjusted PPO for BM (PPO_ADJ) and JH were found for all modalities, but it was higher for runners (r = 0.81) than team and combat sports (r = 0.63 and 0.65, respectively). Moderate agreement generated by the PPO_ADJ and JH was verified in team sports (k = 0.47) and running (k = 0.55) and fair agreement in combat sports (k = 0.29). We conclude that the ratio standard seems to be suitable only for team sports; for runners and combat sports, an allometric model seems adequate. The use of JH as an indicator of power output may be considered reasonable only for runners.

This study analyzed the relationship between generic and judo-specific physical test performances and technical–tactical competition performances among 19 female judo athletes. Participant data were gathered in two stages: (a) physical tests—countermovement jump (CMJ), handgrip strength, Special Judo Fitness Test and Judogi Grip Strength Test; and (b) match performances recorded for technical–tactical analysis. Pearson’s linear correlation and multiple linear regression analysis showed no significant correlations between any technical–tactical parameter and judo-specific physical tests. However, the number of attacks during matches was significantly positively correlated with countermovement jump height (CMJ_JH; r = 0.69, p = .002), peak power output (CMJ_PPO; r = 0.53, p = .002), and peak velocity (CMJ_PV; r = 0.62, p = .001). Effective time during matches was significantly correlated with all CMJ parameters (except maximum force; r = 0.65−0.76, p ≤ .01) and with right hand grip strength ( r = 0.48, p = .037). Match effectiveness was correlated with CMJ_PPO ( r = −0.67, p = .001), mean power output (CMJ_MPO; r = −0.54, p = .017), and CMJ_PV ( r = −0.54, p = .004). The explained power of variance was low for all variables at 45-54%. We conclude that judo-specific performance tests do not seem to be related to female judo athletes’ technical–tactical skills in official competition, though athletes with higher lower limb muscle power and higher handgrip strength showed higher time effectiveness during matches.