Effects of Supplementary Strength-Power Training on Neuromuscular Performance in Young Female Athletes

Children's Sprint and Jump Performance after Plyometric-Jump Training: A Systematic Review

The effect of plyometric jump training on children's jump and sprint performance remains unclear. To explore the effects of PJT on jump and sprint performance in children and to further analyze the influence of participant characteristics and training variables. A literature search was conducted in the PubMed, Web of Science, and SPORTDiscus databases. The included studies (n = 17) involved 587 children, with study sample sizes ranging from 9 to 44 participants. Overall, PJT improved children's vertical jump performance involving squat jump and countermovement jump (ES = 0.78, 95% confidence interval [CI] = 0.41-1.16, I² = 63%, p < 0.01; n = 474), standing long jump performance (ES = 0.56, CI = 0.3-0.83, I² = 26%, p < 0.0001; n = 414), and sprint performance involving 5 m to 30 m distances (ES = -0.41, CI = -0.61 to -0.22, I² = 0%, p < 0.01; n = 424). Subgroup analysis showed non-tapering strategies (ES = 0.92, n = 88) resulted in significant difference than tapering strategies (ES = 0.37, n = 336 np = 0.01). Meta-regression showed a positive correlation between the total number of training sessions and standing long jump performance improvement (p = 0.03). Two studies have a high risk of bias (RoB), and 15 studies have a moderate RoB (some concerns). The GRADE assessment indicated a very low to low robustness of the evidence. In conclusion, PJT can improve children's jump and sprint performance. Increasing the number of training sessions may lead to better standing long jump results. However, the low to very-low robustness of the currently available evidence precludes recommendations regarding PJT for improving children's neuromuscular performance.

Equal Effects of Low- and Moderate-Volume Supplementary Plyometric Training on Sprint, Change of Direction Ability, and Lower-Limb Power in Preadolescent Female Handball Players

Background: This study compared the effects of low- and moderate-volume supplementary plyometric training in preadolescent female handball players. Methods: Thirty-nine preadolescent handball players (age: 12.9 ± 0.5 years, maturity offset: -1.50 ± 0.56 years) were randomly assigned into three groups: low-volume plyometric training group (LPT, n = 12); moderate-volume plyometric training group (MPT, n = 15); and control group (CG, n = 12). The supplementary plyometric training program was performed twice per week for 10 weeks, along with normal training (3 times/week). Each supplementary session included two upper- and three lower-body exercises performed for two sets (LPT, 36-54 foot contacts, duration 12 min) or four sets (MPT, 72-108 foot contacts, duration 24 min). The CG performed technical handball drills for 20 min. Results: Compared with the control group, both LPT and MPT resulted in similar improvements in modified T-test performance (15.1% and 18.6%, p < 0.01, respectively); linear sprint performance over 5, 10, and 20 m (between 5.1% and 8.8%, p = 0.02 to 0.001); countermovement jump (28.0% and 22.1%, p < 0.05, respectively); and standing long jump (12.6% and 12.5%, p = 0.024, respectively). Handgrip strength and overarm shot ball velocity improved similarly in all groups (CG, MPT, and LPT), by 8-11% (p < 0.01). Conclusions: Very-low-volume supplementary plyometric training performed for 12 min per session for two sessions per week results in considerable improvements in running speed, change of direction ability, and leg power and is as effective as a moderate-volume program. These findings are important for pre-adolescent female team sports players, who may benefit from a minimal but effective supplementary training, resulting in large benefits in leg speed and power.

Effects of Neuromuscular Training on Muscle Architecture, Isometric Force Production, and Stretch-Shortening Cycle Function in Trained Young Female Gymnasts

ABSTRACT

Moeskops, S, Oliver, JL, Radnor, JM, Haff, GG, Myer, GD, Ramachandran, AK, Kember, LS, Pedley, JS, and Lloyd, RS. Effects of neuromuscular training on muscle architecture, isometric force production, and stretch-shortening cycle function in trained young female gymnasts. J Strength Cond Res 38(9): 1640-1650, 2024-This study evaluated the effects of a 10-month neuromuscular training (NMT) intervention on muscle architecture, isometric force production, and stretch-shortening cycle (SSC) function. Thirty-seven girls aged 6-12 years were placed into gymnastics + NMT (gNMT; n = 15), gymnastics only (GYM; n = 10), or maturity-matched control (CON; n = 12) groups. The gNMT group followed a 10-month NMT program in addition to gymnastics training, whereas the GYM group only participated in gymnastics training. Isometric midthigh pull (IMTP) and drop jump (DJ) kinetics were measured, in addition to muscle thickness, fascicle length, and pennation angle of the gastrocnemius medialis at baseline and at 4, 7, and 10 months. A 3 × 4 (group × time) repeated-measures ANCOVA (covariate, % predicted adult height) was used to evaluate within-group changes. Significance level was set at p < 0.05. Significant interaction effects were observed in muscle thickness, absolute (PF abs ) and relative peak force (PF rel ) in the IMTP and various DJ variables. The gNMT group demonstrated improvements in muscle thickness, IMTP PF abs and PF rel , and DJ kinetics, most commonly evidenced from 7 months onward. The GYM group's muscle thickness also significantly improved, accompanied by improvements in some DJ kinetics. The CON group did not experience any desirable changes. Overall, NMT elicited positive changes in muscle thickness, PF abs and PF rel , and SSC function to a greater extent than gymnastics training alone or growth and maturation. As most adaptations took 7 months, longer-term NMT programs should be implemented with youth female gymnasts.

Core training and performance: a systematic review with meta-analysis

The purposes were to synthesize as much scientific evidence as possible to determine the effect of core training on balance, throwing/hitting velocity or distance, and jumping in healthy subjects, identify the possible differences between isolated and combined core training on performance and study training and sample variables related to performance. PRISMA guidelines were followed, and a systematic search was performed in the Scopus, Web of Science, Sports Discuss, and PubMed databases with no date restrictions until November 2022. The studies were considered for this meta-analysis following PICO; a) randomized control trials and randomized allocation studies with healthy subjects and > 12 years old b)isolated or combined core training programs with a minimum of 4 weeks in length; c) athletic performance outcomes for balance, throw/hit, and jump variables should be measured; d) sufficient data to calculate effect sizes. The Cochrane Collaboration Risk of Bias Tool and the Grading of Recommendations Assessment, Development, and Evaluation approach were used for assessing methodological quality. A total of 3223 studies were identified, 22 studies were included in the systematic review and 21 for the meta-analysis. We observed that core training improved balance outcomes (ES = 1.17; p < 0.0001), throwing/hitting velocity (ES = 0.30; p = 0.14), throwing/hitting distance (ES = 3.42; p = 0.03), vertical jumping (ES = 0.69; p = 0.0003), and horizontal jump (ES = 0.84; p = 0.01). Our findings indicate that core training improved different variables of performance such as balance, throw/hit, and vertical and horizontal jump.