Refine
Has Fulltext
- no (3)
Year of publication
- 2018 (3) (remove)
Language
- English (3) (remove)
Is part of the Bibliography
- yes (3)
Keywords
- change of direction (1)
- football (1)
- jumping (1)
- maturity (1)
- stretch-shortening cycle (1)
- training optimization (1)
Institute
Background
Jump training (JT) can be used to enhance the ability of skeletal muscle to exert maximal force in as short a time as possible. Despite its usefulness as a method of performance enhancement in athletes, only a small number of studies have investigated its effects on muscle power in older adults.
Objectives
The aims of this meta-analysis were to measure the effect of JT on muscular power in older adults (≥ 50 years), and to establish appropriate programming guidelines for this population.
Data Sources
The data sources utilised were Google Scholar, PubMed, and Microsoft Academic.
Study Eligibility Criteria
Studies were eligible for inclusion if they comprised JT interventions in healthy adults (≥ 50 years) who were free of any medical condition that could impair movement.
Study Appraisal and Synthesis Methods
The inverse variance random-effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis while accounting for heterogeneity across studies. Effect sizes (ESs), calculated from a measure of muscular power, were represented by the standardised mean difference and were presented alongside 95% confidence intervals (CIs).
Results
Thirteen training groups across nine studies were included in this meta-analysis. The magnitude of the main effect was ‘moderate’ (0.66, 95% CI 0.33, 0.98). ESs were larger in non-obese participants (body mass index [BMI] < 30 vs. ≥ 30 kg/m2; 1.03 [95% CI 0.34, 1.73] vs. 0.53 [95% CI − 0.03, 1.09]). Among the studies included in this review, just one reported an acute injury, which did not result in the participant ceasing their involvement. JT was more effective in programmes with more than one exercise (range 1–4 exercises; ES = 0.74 [95% CI − 0.49, 1.96] vs. 0.53 [95% CI 0.29, 0.78]), more than two sets per exercise (range 1–4 sets; ES = 0.91 [95% CI 0.04, 1.77] vs. 0.68 [95% CI 0.15, 1.21]), more than three jumps per set (range 1–14 jumps; ES = 1.02 [95% CI 0.16, 1.87] vs. 0.53 [95% CI − 0.03, 1.09]) and more than 25 jumps per session (range 6–200 jumps; ES = 0.88 [95% CI 0.05, 1.70] vs. 0.49 [95% CI 0.14, 0.83]).
Conclusions
JT is safe and effective in older adults. Practitioners should construct varied JT programmes that include more than one exercise and comprise more than two sets per exercise, more than three jumps per set, and 60 s of recovery between sets. An upper limit of three sets per exercise and ten jumps per set is recommended. Up to three training sessions per week can be performed.
Recently, there has been a proliferation of published articles on the effect of plyometric jump training, including several review articles and meta-analyses. However, these types of research articles are generally of narrow scope. Furthermore, methodological limitations among studies (e.g., a lack of active/passive control groups) prevent the generalization of results, and these factors need to be addressed by researchers. On that basis, the aims of this scoping review were to (1) characterize the main elements of plyometric jump training studies (e.g., training protocols) and (2) provide future directions for research. From 648 potentially relevant articles, 242 were eligible for inclusion in this review. The main issues identified related to an insufficient number of studies conducted in females, youths, and individual sports (~ 24.0, ~ 37.0, and ~ 12.0% of overall studies, respectively); insufficient reporting of effect size values and training prescription (~ 34.0 and ~ 55.0% of overall studies, respectively); and studies missing an active/passive control group and randomization (~ 40.0 and ~ 20.0% of overall studies, respectively). Furthermore, plyometric jump training was often combined with other training methods and added to participants’ daily training routines (~ 47.0 and ~ 39.0% of overall studies, respectively), thus distorting conclusions on its independent effects. Additionally, most studies lasted no longer than 7 weeks. In future, researchers are advised to conduct plyometric training studies of high methodological quality (e.g., randomized controlled trials). More research is needed in females, youth, and individual sports. Finally, the identification of specific dose-response relationships following plyometric training is needed to specifically tailor intervention programs, particularly in the long term.
Ramirez-Campillo, R, Alvarez, C, García-Pinillos, F, Sanchez-Sanchez, J, Yanci, J, Castillo, D, Loturco, I, Chaabene, H, Moran, J, and Izquierdo, M. Optimal reactive strength index: is it an accurate variable to optimize plyometric training effects on measures of physical fitness in young soccer players? J Strength Cond Res 32(4): 885–893, 2018—This study aimed to compare the effects of drop-jump training using a fixed drop-box height (i.e., 30-cm [FIXED]) vs. an optimal (OPT) drop-box height (i.e., 10-cm to 40-cm: generating an OPT reactive strength index [RSI]) in youth soccer players' physical fitness. Athletes were randomly allocated to a control group (n = 24; age = 13.7 years), a fixed drop-box height group (FIXED, n = 25; age = 13.9 years), or an OPT drop-box height group (OPT, n = 24; age = 13.1 years). Before and after 7 weeks of training, tests for the assessment of jumping (countermovement jump [CMJ], 5 multiple bounds), speed (20-m sprint time), change of direction ability (CODA [Illinois test]), strength {RSI and 5 maximal squat repetition test (5 repetition maximum [RM])}, endurance (2.4-km time trial), and kicking ability (maximal kicking distance) were undertaken. Analyses revealed main effects of time for all dependent variables (p < 0.001, d = 0.24–0.72), except for 20-m sprint time. Analyses also revealed group × time interactions for CMJ (p < 0.001, d = 0.51), depth jump (DJ) (p < 0.001, d = 0.30), 20-m sprint time (p < 0.001, d = 0.25), CODA (p < 0.001, d = 0.22), and 5RM (p < 0.01, d = 0.16). Post hoc analyses revealed increases for the FIXED group (CMJ: 7.4%, d = 0.36; DJ: 19.2%, d = 0.49; CODA: −3.1%, d = −0.21; 5RM: 10.5%, d = 0.32) and the OPT group (CMJ: 16.7%, d = 0.76; DJ: 36.1%, d = 0.79; CODA: −4.4%, d = −0.34; 5RM: 18.1%, d = 0.47). Post hoc analyses also revealed increases for the OPT group in 20-m sprint time (−3.7%, d = 0.27). Therefore, to maximize the effects of plyometric training, an OPT approach is recommended. However, using adequate fixed drop-box heights may provide a rational and practical alternative.