scholarly journals The Effects of Plyometric Training on Change-of-Direction Ability: A Meta-Analysis

2016 ◽  
Vol 11 (5) ◽  
pp. 563-573 ◽  
Author(s):  
Abbas Asadi ◽  
Hamid Arazi ◽  
Warren B. Young ◽  
Eduardo Sáez de Villarreal

Purpose:To show a clear picture about the possible variables of enhancements of change-of-direction (COD) ability using longitudinal plyometric-training (PT) studies and determine specific factors that influence the training effects.Methods:A computerized search was performed, and 24 articles with a total of 46 effect sizes (ESs) in an experimental group and 25 ESs in a control group were reviewed to analyze the role of various factors on the impact of PT on COD performance.Results:The results showed that participants with good fitness levels obtained greater improvements in COD performance (P < .05), and basketball players gained more benefits of PT than other athletes. Also, men obtained COD results similar to those of women after PT. In relation to the variables of PT design, it appears that 7 wk (with 2 sessions/wk) using moderate intensity and 100 jumps per training session with a 72-h rest interval tends to improve COD ability. Performing PT with a combination of different types of plyometric exercises such as drop jumps + vertical jumps + standing long jumps is better than 1 form of exercise.Conclusion:It is apparent that PT can be effective at improving COD ability. The loading parameters are essential for exercise professionals, coaches, and strength and conditioning professionals with regard to the most appropriate dose-response trends to optimize plyometric-induced COD-ability gains.

Author(s):  
Marko D. M. Stojanović ◽  
Mladen Mikić ◽  
Patrik Drid ◽  
Julio Calleja-González ◽  
Nebojša Maksimović ◽  
...  

The main aim of the present study was to compare the effects of flywheel strength training and traditional strength training on fitness attributes. Thirty-six well trained junior basketball players (n = 36; 17.58 ± 0.50 years) were recruited and randomly allocated into: Flywheel group (FST; n = 12), traditional strength training group (TST; n = 12) and control group (CON; n = 12). All groups attended 5 basketball practices and one official match a week during the study period. Experimental groups additionally participated in the eight-week, 1–2 d/w equivolume intervention conducted using a flywheel device (inertia = 0.075 kg·m−2) for FST or free weights (80%1 RM) for TST. Pre-to post changes in lower limb isometric strength (ISOMET), 5 and 20 m sprint time (SPR5m and SPR20m), countermovement jump height (CMJ) and change of direction ability (t-test) were assessed with analyses of variance (3 × 2 ANOVA). Significant group-by-time interaction was found for ISOMET (F = 6.40; p = 0.000), CMJ (F = 7.45; p = 0.001), SPR5m (F = 7.45; p = 0.010) and T test (F = 10.46; p = 0.000). The results showed a significantly higher improvement in CMJ (p = 0.006; 11.7% vs. 6.8%), SPR5m (p = 0.001; 10.3% vs. 5.9%) and t-test (p = 0.045; 2.4% vs. 1.5%) for FST compared to the TST group. Simultaneously, th FST group had higher improvement in ISOMET (p = 0.014; 18.7% vs. 2.9%), CMJ (p = 0.000; 11.7% vs. 0.3%), SPR5m (p = 0.000; 10.3% vs. 3.4%) and t-test (p = 0.000; 2.4% vs. 0.6%) compared to the CON group. Players from the TST group showed better results in CMJ (p = 0.006; 6.8% vs. 0.3%) and t-test (p = 0.018; 1.5% vs. 0.6%) compared to players from the CON group. No significant group-by-time interaction was found for sprint 20 m (F = 2.52; p = 0.088). Eight weeks of flywheel training (1–2 sessions per week) performed at maximum concentric intensity induces superior improvements in CMJ, 5 m sprint time and change of direction ability than equivolumed traditional weight training in well trained junior basketball players. Accordingly, coaches and trainers could be advised to use flywheel training for developing power related performance attributes in young basketball players.


BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e039358
Author(s):  
Suhairul Sazali ◽  
Salziyan Badrin ◽  
Mohd Noor Norhayati ◽  
Nur Suhaila Idris

ObjectiveTo determine the effects of coenzyme Q10 (CoQ10) for reduction in the severity, frequency of migraine attacks and duration of headache in adult patients with migraine.DesignSystematic review and meta-analysis.Data sourcesCochrane Central Register of Controlled Trials, CENTRAL, MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Psychological Information Database (PsycINFO) from inception till December 2019.Study selectionAll randomised control trials comparing CoQ10 with placebo or used as an adjunct treatment included in this meta-analysis. Cross-over designs and controlled clinical trials were excluded.Data synthesisHeterogeneity at face value by comparing populations, settings, interventions and outcomes were measured and statistical heterogeneity was assessed by means of the I2 statistic. The treatment effect for dichotomous outcomes were using risk ratios and risk difference, and for continuous outcomes, mean differences (MDs) or standardised mean difference; both with 95% CIs were used. Subgroup analyses were carried out for dosage of CoQ10 and if CoQ10 combined with another supplementation. Sensitivity analysis was used to investigate the impact risk of bias for sequence generation and allocation concealment of included studies.ResultsSix studies with a total of 371 participants were included in the meta-analysis. There is no statistically significant reduction in severity of migraine headache with CoQ10 supplementation. CoQ10 supplementation reduced the duration of headache attacks compared with the control group (MD: −0.19; 95% CI: −0.27 to −0.11; random effects; I2 statistic=0%; p<0.00001). CoQ10 usage reduced the frequency of migraine headache compared with the control group (MD: −1.52; 95% CI: −2.40 to −0.65; random effects; I2 statistic=0%; p<0.001).ConclusionCoQ10 appears to have beneficial effects in reducing duration and frequency of migraine attack.PROSPERO registration numberCRD42019126127.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiao-Ning Zhao ◽  
Quan Sun ◽  
You-Qin Cao ◽  
Xiao Ran ◽  
Yu Cao

Abstract Background Hyperlipidemia plays an important role in the etiology of cardio-cerebrovascular disease. Over recent years, a number of studies have explored the impact of apolipoprotein genetic polymorphisms in hyperlipidemia, but considerable differences and uncertainty have been found in their association with different populations from different regions. Results A total of 59 articles were included, containing in total 13,843 hyperlipidemia patients in the case group and 15,398 healthy controls in the control group. Meta-analysis of the data indicated that APOA5–1131 T > C, APOA1 -75 bp, APOB XbaI, and APOE gene polymorphisms were significantly associated with hyperlipidemia, with OR values of 1.996, 1.228, 1.444, and 1.710, respectively. All P-values were less than 0.05. Conclusions Meta-analysis of the data indicated that the C allele of APOA5 1131 T > C, the A allele at APOA1-75 bp, the APOB XbaI T allele, and the ε2 and ε4 allele of APOE were each a risk factor for susceptibility for hyperlipidemia.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Duygu Akçay ◽  
Nuray Barış

Purpose The purpose of this paper is to evaluate the impact of interventions focused on reducing screen time in children. Design/methodology/approach Studies that aim to investigate the effects of interventions aimed at reducing the time spent in front of the screen (i.e. screen time). A Random-effects model was used to calculate the pooled standard mean differences. The outcome was to evaluate the screen time in children in the 0–18 age range. A subgroup analysis was performed to reveal the extent to which the overall effect size varied by subgroups (participant age, duration of intervention and follow). Findings For the outcome, the meta-analysis included 21 studies, and the standard difference in mean change in screen time in the intervention group compared with the control group was −0.16 (95% confidence interval [CI], −0.21 to −0.12) (p < 0.001). The effect size was found to be higher in long-term (=7 months) interventions and follow-ups (p < 0.05). Originality/value Subgroup analysis showed that a significant effect of screen time reduction was observed in studies in which the duration of intervention and follow-up was =7 months. As the evidence base grows, future researchers can contribute to these findings by conducting a more comprehensive analysis of effect modifiers and optimizing interventions to reduce screen time.


2020 ◽  
Vol 15 (4) ◽  
pp. 512-525 ◽  
Author(s):  
Sam McCormack ◽  
Ben Jones ◽  
Kevin Till

This study aimed to investigate rugby league coaches’ perceptions of physical qualities for current and future performance, while also establishing the training practices of under-16 and under-19 players. Twenty-four practitioners (rugby coach, strength and conditioning coach) working within nine Super League clubs completed a questionnaire. The questionnaire required practitioners to rank eleven physical qualities (i.e. strength, power, acceleration, maximum speed, aerobic endurance, change of direction, agility, height, body mass, lean mass and fat mass) by importance for current performance, future performance and career longevity according to playing position (forwards, backs, hookers and halves). Practitioners were asked to provide detail on the frequency and duration of each type of training session completed during a typical week throughout each phase of the season; pre-season, in-season (early), in-season (mid) and in-season (late). Typically, practitioners ranked strength, power and acceleration qualities highest, and endurance and anthropometric qualities lowest. The importance of physical qualities varied according to each playing level and position. Training practices of under-16 and under-19 players differed during each phase of the season, with under-19 players undertaking greater training volumes than under-16s players. Overall, the physical qualities coaches perceived as most important were not reflected within their training practices. Rugby league practitioners can use this information as a reference source to design long term athletic development plans, prescribe training and during player development procedures. Moreover, these data can inform and improve training practices while influencing the design of pre-season preparatory phases and in-season periods.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Huilin Xu ◽  
Zhucheng Yin ◽  
Anbing He ◽  
Dedong Cao

Background. This meta-analysis aimed to evaluate the efficacy and safety of Javanica oil emulsion injection (JOI) combined with chemotherapy versus chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC). Methods. Electronic databases including EMBASE, PUBMED, the Cochrane library, and Chinese Biological Medical disc (CBM) were searched until May 2018. The clinical trials reporting efficacy and immune function of JOI combined with chemotherapy versus chemotherapy in advanced NSCLC were included according to the inclusion and exclusion criteria. Stata 11 and RevMan 5.3 were used for meta-analysis. Results. Twenty-four studies involving 2089 cases were included. The results of the meta-analysis showed that there were significant differences in objective response rate (risk ratio (RR) = 1.17; 95% confidence interval (CI): 1.05–1.29; P<0.05), improvement in Karnofsky Performance Status (standard mean difference (SMD) = 1.59; 95% CI: 1.41–1.77; P<0.01), incidence of adverse events (RR = 0.78; 95% CI: 0.7–0.87; P<0.05), percentage changes of CD3+ cells (SMD = 2.0; 95% CI: 1.49–2.50; P<0.01), CD4+ cells (SMD = 1.55; 95% CI, 1.2–1.9; P<0.01), natural killer cells (SMD = 1.98; 95% CI: 1.15–2.82; P<0.01), but not CD8+ (SMD = −1.44; 95% CI: −4.53–1.65; P=0.36), and value of CD4+/CD8+ (SMD = 0.32; 95% CI: 0.28–0.36; P<0.01) between the JOI combination group and control group. Funnel plot and Begg’s and Egger’s analysis indicated that there was no significant publication bias (P>0.05). Conclusions. JOI may be effective to improve the efficacy of chemotherapy in advanced NSCLC patients, accompanied with better levels of immune cells.


2020 ◽  
Vol 81 (04) ◽  
pp. 342-347
Author(s):  
Binbin Wu ◽  
Hongyan Yuan ◽  
Deyu Geng ◽  
Liang Zhang ◽  
Cheng Zhang

Abstract Introduction The efficacy of a stabilization exercise for the relief of neck pain remains controversial. We conducted a systematic review and meta-analysis to explore the effectiveness of a stabilization exercise on neck pain. Methods We searched Embase, Web of Science, EBSCO Information Services, and the Cochrane Library databases through May 2019 for randomized controlled trials (RCTs) assessing the impact of a stabilization exercise on neck pain. This meta-analysis was performed using the random effects model. Results Six RCTs are included in the meta-analysis. Compared with the control group of patients with neck pain, a stabilization exercise can significantly reduce pain scores at 4 to 6 weeks (mean difference [MD]: −2.41; 95% confidence interval [CI], −4.46 to −0.35; p = 0.02), Neck Disability Index [NDI] at 10 to 12 weeks (MD:− 6.75; 95% CI, −11.71 to −1.79; p = 0.008), and depression scale at 4 to 6 weeks (MD: −4.65; 95% CI, −7.00 to −2.31; p = 0.02), but it has no obvious impact on pain scores at 10 to 12 weeks (MD: −1.07; 95% CI, −3.42 to 1.28; p = 0.37) or at 6 months (MD: −1.02; 95% CI, −3.43 to 1.39; p = 0.41). Conclusions A stabilization exercise can provide some benefits to control neck pain.


2020 ◽  
Vol 32 (2) ◽  
pp. 81-88 ◽  
Author(s):  
K. Katsikari ◽  
Eleni Bassa ◽  
Dimitrios Skoufas ◽  
Savvas Lazaridis ◽  
Christos Kotzamanidis ◽  
...  

Purpose: To examine the effect of a 10-week plyometric training (PT) on the kinematic and kinetic properties of prepubescent girls during squat jump, countermovement jump, and drop jumps. Methods: Twenty-four untrained girls (aged 9–11 y) were assigned to a training group (TG) and a control group. The TG followed twice a week PT for 10 weeks. Squat jump, countermovement jump, and drop jumps performed from heights of 20, 35, and 50 cm were tested before and after PT. Jump height, kinematic, and kinetic parameters were evaluated using a motion analysis system and a force plate. Results: Jumping height in all jump types increased significantly after PT for the TG (P < .001). After training, the TG presented increased power (P < .001) and knee angular velocity (P < .001), higher knee flexion at the deepest point during the braking phase (P < .001), longer contact time (P < .001), and unchanged stiffness and reaction strength index (P > .05). No differences were observed in the control group (P > .05). Conclusion: These findings indicate that a 10-week PT positively affected jumping performance in prepubescent girls who improved their drop jump performance after training not by adopting a stiff/bouncing jumping style of short contact time and increased stiffness, but a compliant/absorbing style of prolonged contact time.


2019 ◽  
Vol 5 ◽  
pp. 233372141985969 ◽  
Author(s):  
Raphael Miranda Ramos ◽  
Hélio José Coelho-Júnior ◽  
Ricardo Yukio Asano ◽  
Raul Cosme Ramos Prado ◽  
Rodrigo Silveira ◽  
...  

The association of old age and chronic conditions, such as hypertension and obesity, can lead to larger decreases in the physical capacities of elderly, compared with their healthy counterparts. Physical exercise has been demonstrated to be efficient in postponing this phenomenon, mainly strength training. However, little is known about the effect of aerobic training on this condition. The aim of this work was to investigate the impact of 12 weeks of moderate-intensity aerobic training on the physical capacities of hypertensive obese older women. Aerobic power, lower limb muscle power, upper limb muscle strength, endurance, and flexibility of 19 hypertensive obese elders were evaluated. Afterward, patients were blindly randomized into control group (CG) and exercise group (EG). EG underwent three sessions/week of 60 min of moderate-intensity aerobic training, during 12 weeks. EG showed increases in VO2max compared with CG ( p = .03) and increases in flexibility compared with basal moment (+21.6%; p = .01) after 12 weeks, whereas CG did not show any significant alterations. Moderate aerobic training is capable of inducing increases in maximal aerobic power and flexibility in hypertensive obese elderly. However, other essential physical capacities associated with independence in elderly people (i.e., muscle power and strength) were not responsive to this kind of protocol.


2015 ◽  
Vol 10 (6) ◽  
pp. 767-773 ◽  
Author(s):  
Alexandre Moreira ◽  
Tom Kempton ◽  
Marcelo Saldanha Aoki ◽  
Anita C. Sirotic ◽  
Aaron J. Coutts

Purpose: To examine the impact of varying between-matches microcycles on training characteristics (ie, intensity, duration, and load) in professional rugby league players and to report on match load related to these between-matches microcycles. Methods: Training-load data were collected during a 26-wk competition period of an entire season. Training load was measured using the session rating of perceived exertion (session-RPE) method for every training session and match from 44 professional rugby league players from the same National Rugby League team. Using the category-ratio 10 RPE scale, the training intensity was divided into 3 zones (low <4 AU, moderate ≥4-≤7 AU, and high >7 AU). Three different-length between-matches recovery microcycles were used for analysis: 5−6 d, 7−8 d, and 9−10 d. Results: A total of 3848 individual sessions were recorded. During the shorter-length between-matches microcycles (5−6 d), significantly lower training load was observed. No significant differences for subsequent match load or intensity were identified between the various match recovery periods. Overall, 16% of the training sessions were completed at the low-intensity zone, 61% at the moderate-intensity zone, and 23% at the high-intensity zone. Conclusions: The findings demonstrate that rugby league players undertake higher training load as the length of between-matches microcycles is increased. The majority of in-season training of professional rugby league players was at moderate intensity, and a polarized approach to training that has been reported in elite endurance athletes does not occur in professional rugby league.


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