Optimised force-velocity training during pre-season enhances physical performance in professional rugby league players     

Adam Simpson  Mark Waldron  Emily Cushion  Jamie Tallent 《Journal of sports sciences》2021,39(1):91-100

ABSTRACT

The effectiveness of 8-week force-velocity optimised training was assessed in highly trained professional rugby league athletes. Players (age 24 ± 3 years; body mass 94.9 ± 21.6 kg; height 181.3 ± 6.0 cm) were strength-matched and assigned to a force-velocity optimised group (OP; n = 15) or a general strength-power group (GP; n = 14). Tests included 10-m, 20-m sprints, 3 repetition-maximum squat and squat jumps over five load conditions to ascertain vertical force-velocity relationship. ANCOVA revealed there was a group effect for force-velocity deficit (P < 0.001), with the OP two-fold greater than the GP group (OP pre: 51.13 ± 31.42%, post: 62.26 ± 31.45%, GP pre: 33.00 ± 19.60%, post: 31.14 ± 31.45%, P < 0.001). There were further group effects for 3RM squat (OP pre: 151.17 ± 22.95 kg, post: 162.17 ± 24.16 kg, GP pre: 156.43 ± 25.07 kg, post: 163.39 ± 25.39 kg, P < 0.001), peak power (OP pre: 3195 ± 949 W, post: 3552 ± 1033 W, GP pre: 3468 ± 911 W, post: 3591 ± 936 W, P < 0.001), and SJ (OP pre: 39.79 ± 7.80 cm, post: 42.69 ± 7.83 cm, GP pre: 40.44 ± 6.23 cm, post: 41.14 ± 5.66 cm, P < 0.001). Prescribing F-V deficit training is superior for improving physical performance within highly trained RL players.  相似文献   

基于知识元的学术论文内容创新性智能化评价研究   总被引：1，自引：0，他引：1  

李贺  杜杏叶 《图书情报工作》2020,64(1):93-104

[目的/意义] 创新性是对学术论文质量最基本的要求，是学术论文的灵魂，是学术论文评价的核心。知识元是学术论文基本组成单元。基于知识元理论和机器学习相关理论与算法，从学术论文内容层面研究计算机如何智能化地进行创新性评价及其实现过程与方法。[方法/过程] 首先，构建学术论文的研究问题、理论、方法、结论4个知识元本体，接着提出基于知识元的学术论文创新性判断模型。其次，根据学术论文研究特点，构建理论与方法机器分类模型及知识元的抽取规则与抽取方法，建立规则库和知识语料库。最后，基于语义相似度计算方法，根据判断规则和相关权重对学术论文4个维度的创新性进行评分。[结果/结论] 基于知识元抽取的学术论文创新性评分系统的实证结果表明，该智能化评价方法具有一定的可行性，可为学术论文内容创新性智能化评价系统的最终实现提供方法借鉴。  相似文献   

PCSI:一种单篇论文被引频次标准化方法     

伍军红  肖宏  任美亚  冯士雍  丁哲 《图书情报工作》2020,64(23):22-30

[目的/意义] 文章的被引频次一直是量化评价一篇论文学术影响力的重要指标。但在不同学科不同年份发表的论文会因该领域研究论文数、引用滞后等因素呈现较大的差异。因此在对比两篇论文时，难以简单依据被引频次的绝对值来评判论文影响力大小。为此，本文设计了一个新的可计算数学模型，使得每篇论文可以有一个标准化的指标，以便对不同学科不同年份发表的论文的学术影响力进行直接比较。[方法/过程] 通过分析2006、2017两年中国科技类学术期刊各学科论文的被引频次分布规律，采用同学科论文被引频次的分布形态最接近对数正态分布的先设条件，提出一种被引频次标准化指数——Paper Citation Standardized Index （简称PCSI，中文"论文引证标准化指数"）。最后以中国科协优秀科技期刊论文评选结果为例，将它们与论文所属学科全部论文进行实证对比研究。[结果/结论] 结果证明，PCSI对不同年份、不同学科论文的被引频次进行了标准化，反映了被引频次的线性差距，是一种较为理想的单篇论文学术影响力比较评价工具。  相似文献   

我国少数民族传统体育在构建体育强国中的作用     

杨明 《当代体育科技》2020,(12):217-218

少数民族传统体育作为我国民族体育的重要组成部分,具有鲜明的民族性和地域性。少数民族传统体育是我国迈向体育强国的动力杠杆,起着重要的推动作用,也是实现全民健身的重要途径。当今,我国距离实现体育强国的梦想还有许多路要走,只有落实和发展好群众体育,才能更好地助推我国体育强国梦的早日实现。我国少数民族众多,体育文化丰姿多彩,当地独特厚重的体育文化资源是助推我国早日实现体育强国梦的重要支柱和保障。  相似文献   

媒介权力对体育媒体传播中女性形象的影响研究*     

刘〓婷  宋宗佩  冯培明  孙晨晨 《广州体育学院学报》2020,(3):46-49

媒介权力作为第四种权力，影响着媒介形象的塑造。运用文献资料、逻辑分析和理论分析等研究方法，就媒介权力对女性形象的影响进行研究。研究发现，社会责任理论要求，体育媒体有必要塑造健康的女性形象。受媒介权力的正面影响，体育媒体中女性形象的塑造，表现出传播主体多元化、传播内容丰富化、传播途径多样化和传播受众理性化等特征。然而，以媒介缺位、媒介错位和媒介越位为表征的媒介权力异化，塑造了有偏差的女性形象，引发了受众对女性的不合理认知。未来受媒介权力的影响，体育媒体应在全媒介时代背景下丰富女性体育传播媒介，机会均等观念下均衡配备传播主体，性别平等理念下合理发布传播内容，培养理论视域下积极引导传媒受众，以促进体育领域性别平等观念的发展。  相似文献   

纳米流体液滴撞击固体壁面的实验和模拟研究     

王睿  沈学峰  霍元平  王军锋  郑诺  刘海龙 《中国科学院大学学报》2020,37(2):281-287

液滴撞击固体壁面现象常见于动力机械、喷雾冷却和薄膜材料沉积制备等工业生产中。将石墨烯和碳纳米管作为分散颗粒，应用超声波分散技术制备均匀性与稳定性良好的树脂基纳米流体。利用高速摄像技术，研究纳米流体液滴撞击固体壁面的动力学行为。基于有限元法，通过修正的幂律黏度模型耦合纳米流体的剪切变稀特性，采用水平集方法捕捉相界面的移动，建立纳米流体液滴撞击固体壁面的数值模型。模拟结果与实验结果较好一致，验证了数值模型的正确性与准确性。研究发现实验配制的纳米流体表现出非牛顿剪切变稀特性，纳米颗粒的加入抑制了液滴撞击固体壁面过程中的铺展和回缩行为。随着幂律指数m的减小，液滴撞击固体壁面后的铺展范围变大。随着表面张力的增大，液滴的无量纲直径在铺展阶段无明显变化，但在回缩阶段逐渐减小。  相似文献   

技巧啦啦操运动员核心力量训练内容及其方法的研究     

李焕君 《当代体育科技》2020,(10):242-243

技巧啦啦操在国内快速的普及,大大小小的比赛也越来越多,从幼儿园到大学各种各样的技巧啦啦操队伍也应运而生,参与比赛的人说也是逐年增加,但运动员的技巧水平还有待提高,身体素质也有待加强。鉴于这些薄弱方面,本文主要运用文献资料法、访谈法、逻辑分析法等对技巧啦啦操运动员的核心力量训练内容及其方法进行研究,旨从理论中指导实践,从实践中总结经验,推动我国的技巧啦啦操水平向世界先进水平迈进,从而走得更远。  相似文献   

我国体育行政执法方式改革研究          下载免费PDF全文

梁尧 《体育科研》2019,(4):67-74

新时代对体育强国和体育法治建设提出了新要求，行政执法作为体育强国建设的重要抓手也面临着方式革新的机遇和挑战。简政放权背景下，体育执法面临着“应不应该管、怎样管”的尴尬处境，广为体育行政执法主体运用的强制性执法手段极易加剧执法矛盾，执法的社会效果得不到保障。由于传统执法方式难以适应新时代体育市场监管的现实需要，革新体育行政执法方式就显得尤为必要。面对时代课题，应遵照由“形式优化”到“实质革新”的逻辑，并树立行政平衡、服务合作和正当程序的理念，从引入信用工具、推广非强制性执法和全程说理式执法3个方面推进改革，实现体育行政执法方式的精简化、多元化和法治化。  相似文献   

Validity and reliability of a linear positional transducer across commonly practised resistance training exercises     

Harry F. Dorrell  Joseph M. Moore  Mark F. Smith  Thomas I. Gee 《Journal of sports sciences》2019,37(1):67-73

This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R² values of >0.85 for all variables excluding deadlift mean velocity (R² = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.  相似文献   

Reference power values for the jump squat exercise in elite athletes: A multicenter study     

Pedro L. Valenzuela  Michael McGuigan  Guillermo Sánchez-Martínez  Elaia Torrontegi  Javier Vázquez-Carrión  Zigor Montalvo 《Journal of sports sciences》2020,38(19):2273-2278

ABSTRACT

The present study aimed to provide reference values for lower-limb muscle power assessed during the incremental jump squat (JS) test in elite athletes (i.e., professional athletes competing at international level). We pooled data from all JS tests performed by elite athletes of different sports in two high-performance centres between 2015 and 2019, and computed reference values (i.e., terciles) for mean power (MP), mean propulsive power (MPP), and peak power (PP). Reference values were obtained from 684 elite athletes (458 male and 226 female) of 16 different sports (boxing, judo, karate, fencing, taekwondo, wrestling, basketball, soccer, futsal, handball, rugby union, badminton, tennis, long distance running, triathlon, and sprinting). Significant differences (p < 0.001) were found between male and female athletes for MP (7.47 ± 1.93 and 6.15 ± 1.68 W·Kg^?1, respectively), MPP (10.50 ± 2.75 and 8.63 ± 2.43 W·Kg^?1), and PP (23.64 ± 6.12 and 19.35 ± 5.49 W·Kg^?1). However, the velocity at which these power measures was attained seemed to be independent of sex (~0.95, 1.00 and 2.00 m·s^?1 for mean, mean propulsive, and peak velocity, respectively) and homogeneous across different sport disciplines (coefficient of variation <10%). These data can be used to classify athletes’ power capabilities, and the optimum velocity ranges provided here could be useful for training purposes.  相似文献