TY - JOUR A1 - Chaouachi, Mehdi A1 - Granacher, Urs A1 - Makhlouf, Issam A1 - Hammami, Raouf A1 - Behm, David G. A1 - Chaouachi, Anis T1 - Within Session Sequence of Balance and Plyometric Exercises Does Not Affect Training Adaptations with Youth Soccer Athletes JF - Journal of sports science & medicine N2 - The integration of balance and plyometric training has been shown to provide significant improvements in sprint, jump, agility, and other performance measures in young athletes. It is not known if a specific within session balance and plyometric exercise sequence provides more effective training adaptations. The objective of the present study was to investigate the effects of using a sequence of alternating pairs of exercises versus a block (series) of all balance exercises followed by a block of plyometric exercises on components of physical fitness such as muscle strength, power, speed, agility, and balance. Twenty-six male adolescent soccer players ( 13.9 +/- 0.3 years) participated in an 8-week training program that either alternated individual balance (e. g., exercises on unstable surfaces) and plyometric (e. g., jumps, hops, rebounds) exercises or performed a block of balance exercises prior to a block of plyometric exercises within each training session. Pre- and post-training measures included proxies of strength, power, agility, sprint, and balance such as countermovement jumps, isometric back and knee extension strength, standing long jump, 10 and 30-m sprints, agility, standing stork, and Y-balance tests. Both groups exhibited significant, generally large magnitude (effect sizes) training improvements for all measures with mean performance increases of approximately > 30%. There were no significant differences between the training groups over time. The results demonstrate the effectiveness of combining balance and plyometric exercises within a training session on components of physical fitness with young adolescents. The improved performance outcomes were not significantly influenced by the within session exercise sequence. KW - Power KW - strength KW - jumps KW - sprints KW - balance KW - children Y1 - 2017 SN - 1303-2968 VL - 16 SP - 125 EP - 136 PB - Department of Sports Medicine, Medical Faculty of Uludag University CY - Bursa ER - TY - JOUR A1 - Hortobagyi, Tibor A1 - Lesinski, Melanie A1 - Fernandez-del-Olmo, Miguel A1 - Granacher, Urs T1 - Small and inconsistent effects of whole body vibration on athletic performance: a systematic review and meta-analysis JF - European journal of applied physiology N2 - We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Systematic literature review and meta-analysis. Whole body vibration combined with exercise had an overall 0.3 % acute effect on maximal voluntary leg force (-6.4 %, effect size = -0.43, 1 study), leg power (4.7 %, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 %, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 %, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 % chronic effect on maximal voluntary leg force (14.6 %, weighted mean effect size = 0.44, 5 studies), leg power (10.7 %, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 %, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 %, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance. KW - Exercise KW - Muscle KW - Force KW - Power KW - Skill KW - Reflex KW - Endocrine KW - Metabolism Y1 - 2015 U6 - https://doi.org/10.1007/s00421-015-3194-9 SN - 1439-6319 SN - 1439-6327 VL - 115 IS - 8 SP - 1605 EP - 1625 PB - Springer CY - New York ER - TY - JOUR A1 - Behm, David G. A1 - Alizadeh, Shahab A1 - Drury, Ben A1 - Granacher, Urs A1 - Moran, Jason T1 - Non-local acute stretching effects on strength performance in healthy young adults JF - European journal of applied physiology N2 - Background Static stretching (SS) can impair performance and increase range of motion of a non-exercised or non-stretched muscle, respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature. Methods A systematic literature search following preferred reporting items for systematic review and meta-analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The physiotherapy evidence database scale was used to assess study risk of bias and methodological quality. Results Unilateral stretching protocols from six studies involved 6.3 +/- 2 repetitions of 36.3 +/- 7.4 s with 19.3 +/- 5.7 s recovery between stretches. The mean stretch-induced force deficits exhibited small magnitude effect sizes for both the stretched (-6.7 +/- 7.1%, d = -0.35: 0.01 to -1.8) and contralateral, non-stretched, muscles (-4.0 +/- 4.9%, d = , 0.22: 0.08 to 1.1). Control measures exhibited trivial deficits. Conclusion The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude force deficits. However, the frequency of studies with these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global (non-local) effects of prolonged SS. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others. KW - Flexibility KW - Power KW - Crossover KW - Fatigue KW - Mental fatigue KW - Neural inhibition Y1 - 2021 U6 - https://doi.org/10.1007/s00421-021-04657-w SN - 1439-6319 SN - 1439-6327 VL - 121 IS - 6 SP - 1517 EP - 1529 PB - Springer CY - Berlin ; Heidelberg ER - TY - JOUR A1 - Matuschek, Hannes A1 - Kliegl, Reinhold A1 - Vasishth, Shravan A1 - Baayen, Harald R. A1 - Bates, Douglas T1 - Balancing Type I error and power in linear mixed models JF - Journal of memory and language N2 - Linear mixed-effects models have increasingly replaced mixed-model analyses of variance for statistical inference in factorial psycholinguistic experiments. Although LMMs have many advantages over ANOVA, like ANOVAs, setting them up for data analysis also requires some care. One simple option, when numerically possible, is to fit the full variance covariance structure of random effects (the maximal model; Barr, Levy, Scheepers & Tily, 2013), presumably to keep Type I error down to the nominal a in the presence of random effects. Although it is true that fitting a model with only random intercepts may lead to higher Type I error, fitting a maximal model also has a cost: it can lead to a significant loss of power. We demonstrate this with simulations and suggest that for typical psychological and psycholinguistic data, higher power is achieved without inflating Type I error rate if a model selection criterion is used to select a random effect structure that is supported by the data. (C) 2017 The Authors. Published by Elsevier Inc. KW - Power KW - Linear mixed effect model KW - Hypothesis testing Y1 - 2017 U6 - https://doi.org/10.1016/j.jml.2017.01.001 SN - 0749-596X SN - 1096-0821 VL - 94 SP - 305 EP - 315 PB - Elsevier CY - San Diego ER -