Relationships among birth-month distribution,skeletal age and anthropometric characteristics in adolescent elite soccer players

Abstract

The aim of the present study was to clarify relationships among the distribution of birth month, maturation and body size in young soccer players. We therefore examined physical and maturational differences between selected players, who were considered to have higher potential to play soccer at a professional level as decided subjectively by coaches, and unselected players. Participants were 332 elite soccer players (mean age = 12.2 ± 1.5 years; range = 9.1–15.0 years). Participants were divided into six categories (under = U10 to U15), depending on chronological age. Height, body mass skeletal age and maturation difference (skeletal age – chronological age) were compared among four groups (quarter = Q1 to Q4) depending on month of birth. Overall, the distribution of players across the four quarters was skewed such that numbers were greatest in Q1 and smallest in Q4. No significant differences in maturation difference were observed between birth quarters in any age category. On the other hand, except for the U14 age category, there were no significant differences in height between Q4 and Q1 players. However, the height of Q4 players was significantly smaller than those of Q1 in three (U11, U13 and U14, P < 0.01) of six categories when maturation difference was statistically controlled. Our results suggest a clear bias toward quarter of birth and this bias may depend to some extent on differences in individual skeletal age and body size. Individual biological maturation should thus be considered when selecting adolescent soccer players.     

Discriminant analysis of anthropometric and biomotor variables among elite adolescent female athletes in four sports

The aim of this study was to identify anthropometric and biomotor variables that discriminated among groups of elite adolescent female athletes aged 14.3 ± 1.3 years (mean ± s) from four different sports (tennis, n = 15; swimming, n = 23; figure skating, n = 46; volleyball, n = 16). The anthropometric variables included body mass, height, bi-epicondylar breadth of the distal extremity of the humerus and femur, maximal girth of the calf and biceps and the sum of five adipose skinfolds. The biomotor variables were maximal aerobic power, muscular endurance and flexibility of the trunk. Discriminant analysis revealed three significant functions (P ? 0.05). The first discriminant function primarily represented differences between figure skaters and all other groups of athletes. The other two underlined anthropometric and biomotor differences between swimmers and volleyball players and between tennis players and swimmers, respectively. After validation, the analysis showed that 88% of the athletes were correctly classified in their respective sports. Our model confirms that elite adolescent female athletes show physical and biomotor differences that clearly distinguish them according to their particular sport.     

Discriminant analysis of anthropometric and biomotor variables among elite adolescent female athletes in four sports

The aim of this study was to identify anthropometric and biomotor variables that discriminated among groups of elite adolescent female athletes aged 14.3 +/- 1.3 years (mean +/- s) from four different sports (tennis, n = 15; swimming, n = 23; figure skating, n = 46; volleyball, n = 16). The anthropometric variables included body mass, height, bi-epicondylar breadth of the distal extremity of the humerus and femur, maximal girth of the calf and biceps and the sum of five adipose skinfolds. The biomotor variables were maximal aerobic power, muscular endurance and flexibility of the trunk. Discriminant analysis revealed three significant functions (P < 0. 05). The first discriminant function primarily represented differences between figure skaters and all other groups of athletes. The other two underlined anthropometric and biomotor differences between swimmers and volleyball players and between tennis players and swimmers, respectively. After validation, the analysis showed that 88% of the athletes were correctly classified in their respective sports. Our model confirms that elite adolescent female athletes show physical and biomotor differences that clearly distinguish them according to their particular sport.     

不同水上运动项目优秀运动员肱二头肌微循环相关指标的研究

目的：探讨不同水上运动项目优秀男子运动员安静状态下肱二头肌微循环相关指标与运动项目、运动员等级及专项训练年限的关系方法：利用PeriFlux Syste m 5000系列激光多普勒仪自带的血流单元、温控单元及经皮氧分压单元,对47名不同水上运动项目抛秀男子运动员进行安静、坐位状态下肱二头肌微循环相关指标进行测试,测试环境为室内,室温250±3．0℃、空气相对湿度45．0％～65．0％,结果：不同水上运动项目优秀男子运动员肱二共肌微循环血流灌注量（PU）、血细胞的运动速率（V）、经皮氧分压（tcpO2）皮艇组〉赛艇组〉帆船组,加热后PU变化率帆船组〉赛艇组〉皮艇组,加热后微循环相关指标变化率帆船组〉皮艇组;不同运动等级水上运动项目优秀男子运动员安静时肱二头肌PU、V一级运动员组〉二级运动员组〉健将级运动员组,而加热后PU的变化率、运动的血细胞聚集程度（CMBC）的变化率健将级运动员组〉一级运动员组〉二级运动员组;不同专项训练年限水上运动项目优秀男子运动员安静时肱二头肌微循环PU、V1-5年组〉6～9年组〉10年以上组,结论不同水上运动项目优秀男子运动员安静状态下肱二头肌部分微循环相关指标与运动项目、运动员等级及运动员专项训练年限有关。     

The role of anthropometric,performance and psychological attributes in predicting selection into an elite development programme in older adolescent rugby league players

This study aimed to identify attributes that discriminate selected from non-selected players and predict selection into a rugby league development programme in older adolescent players. Anthropometric, performance and psychological attributes were measured in under-16 (N = 100) and under-18 (N = 60) rugby league players trialling for selection into a development programme with a professional Australian club. Sprint times (P < 0.001), predicted VO_2max (P = 0.002) and push-ups_1 min (P = 0.004) were superior in selected under-16 players, and sprint times (P ≤ 0.045), push-ups_1 min (P < 0.001) and chin-ups_1 min (P = 0.013) were superior in selected under-18 players. Further, 10-m sprint (β = ?7.706, standard error [SE] = 2.412), VO_2max (β = 0.168, SE = 0.052) and body mass (β = 0.071, SE = 0.023) significantly predicted selection (R² = 0.339) in under-16 players, while push-ups_1 min (β = 0.564, SE = 0.250), 10-m sprint (β = ?68.477, SE = 28.107), body mass (β = 0.360, SE = 0.155) and chronological age (β = ?3.577, SE = 1.720) significantly predicted selection (R² = 0.894) in under-18 players. These findings emphasise the importance of performance attributes in junior rugby league and indicate talent identification test batteries should be age-specific in older adolescent players.     

Factors affecting sports involvement in a school-based youth cohort: Implications for long-term athletic development

ABSTRACT

The aim of the present study was to determine the factors affecting sports involvement in a school-based adolescent population. The cross-sectional cohort study assessed anthropometry, physical capacities and motor competence in 501 boys (aged 10–16 y), from junior (10–12 y) and senior (13–16 y) cohorts. Sports participation data was collected from junior participants. Multivariate analysis of covariance revealed moderate maturity, anthropometry, physical capacity and motor competence differences between sports in the senior cohort (F = 2.616, p < 0.001, η² = .08), but not in the junior cohort. Furthermore, differences in physical fitness were revealed between playing levels (F = 2.616, p < 0.001, η² = .08), with a discriminant analysis correctly classifying 73% of participants using aerobic fitness and vertical jump measures. Representative level participants engaged in more structured training and commenced organised competition at a later age (F = 4.332, p < 0.001, η² = .21). This study’s findings are twofold: 1) physical and motor competence profiles differ more between sports with increasing age, and 2) participants at a higher level of competition report delayed engagement in their main sport. As a result, schools may be the ideal environment in which to provide children and adolescents with the opportunity to sample different sports.     

体能主导类项群教练员行为特点研究

向辽宁队、北京队、山东队、上海队、广东队、河南队、四川队、甘肃队以及部分项目国家集训队的体能主导类项群教练员发放问卷共计800份，通过对回收的有效问卷645份进行统计分析，并结合个案观察和访谈的结果，对我国优秀运动队不同项群教练员行为（选材行为、训练行为、比赛行为、管理行为）特点逐一进行研究探讨和对比分析，为项群理论建设和发展中对不同项群教练员行为特点的归纳，进行了理论和实践上的初步探索。     

我国优秀运动员运动寿命的项群差异

通过比较连续3届进入全运会决赛运动员的项群分布，发现我国不同项群的优秀运动员运动寿命有所不同，技能类项群的运动员运动寿命长于体能类项群运动员。在技能类项群中，运动寿命较长的是球类运动员，而格斗类项目的运动员运动寿命较短。而在体能类项群中，速度性项目运动员的运动寿命长于耐力性和快速力量性项目运动员的运动寿命。     

普通高校高水平运动队建设的影响因素与发展对策

分析了我国高校高水平运动队建设中教育与体育体制的分离，训练经费不足，教练员既从事体育教学又从事业余训练而致负担过重，运动员的先天不足、就业困难与体育科研力量薄弱等影响因素，并指出只有发挥高等学校、竞技体育系统和社会力量的作用，使竞技体育院校化，解决引进和培养优秀教练员等问题，才能加速推进我国高校高水平运动队建设水平，并走上健康的可持续发展道路，培养出更多更优秀的竞技体育人才。     

Division,result and score margin alter the physical and technical performance of elite wheelchair tennis players

ABSTRACT

This study determined the physical and technical demands of elite wheelchair tennis (WT) match-play, how the demands differed between divisions (Men, Women, Quad) and the effect that set result and score margin had on these demands. Seventeen WT players were monitored during a singles competition. Physical measures of performance were analysed using an indoor tracking system and inertial measurement units. Technical measures of performance were examined using video analysis. Physical measures of performance differed by division (Men > Women > Quad) for most parameters. Rallies were longer during Men’s (P = 0.027) and Women’s (P = 0.004) matches compared to Quad’s and fewer shots were hit off 2 bounces in Men’s matches compared to Women’s and Quad’s (P ≤ 0.026). High-speed activity (HSA) increased during losing sets (P = 0.043). Most physical measures of performance increased by moderate to large effects during sets with a small score margin (≤3 games differential). Mean speed and HSA were similar during losing sets, regardless of margin, but decreased (large effects) when winning by a large margin. This study demonstrated the physical and technical demands that elite WT players need to be prepared for and how situational factors can influence these demands.     

我国高校竞技体育的现实审视及对策研究

目的:从高校竞技体育的现实状况出发,深入分析制约高校竞技体育发展的瓶颈,提出对策。研究认为:由于高校竞技体育发展的目标和定位不准确、竞技体育项目设置不均衡、运动员文化教育缺失、运行体制不完善以及教练员队伍结构不合理等问题,致使高校竞技体育不能更好的发挥功能和作用。随着高等教育改革的不断深入,高校人才培养观念的不断更新,高校竞技体育建设工作提出了新的更高要求。高校应该权衡利弊,深入矛盾根源,制定改革措施,以实现高校竞技体育的可持续发展。     

不同情景中体育专业与非体育专业大学生目标定向差异比较研究

目标定向理论是研究个体在成就情景中的动机和行为的理论。运动和学业任务定向及运动和学业自我定向在高校体育专业和非体育专业的大学生中都显示出非常显著性的相关,运动情景中目标定向和学业情景中目标定向在两种情景中可能存在着某种迁移现象。     

Differences in self-regulatory skills among talented athletes: The significance of competitive level and type of sport

Abstract

Research has shown that talented athletes outscore their mainstream peers on the basis of self-regulation. Although valuable, this does not tell us more about the distinction between good athletes and the best, which is a prerequisite in talent development. Therefore, we examined the self-regulatory skills of 222 male and female talented athletes aged 12–16 years as a function of competitive sport level (junior international or junior national athletes) and type of sport (individual or team sports). Multivariate analyses of covariance in combination with a discriminant function analysis revealed that “reflection” distinguishes between athletes at the highest levels of excellence. Furthermore, athletes playing individual sports had higher scores on “planning” and “effort” than team sport athletes, highlighting the importance of differences between types of sport. In conclusion, we emphasize the importance of reflection as a self-regulatory skill. Reflection facilitates the development of sport-specific characteristics, which may vary by type of sport. This means that an advanced sense of reflection may help talented athletes to acquire desirable characteristics during their “talent” years to ultimately reach adult elite levels of competition.     

欧美体育强国竞技体育人才培养模式及启示

运用文献资料法、逻辑分析法等,对欧美体育强国的人才培养模式进行梳理与探析。结果表明:无论具体进行管理的主体是政府、俱乐部、体育协会或其他,培养模式均依托学校教育的优势与提供的资源,为加快我国体育强国的建设,需要进一步深化体教结合模式,加强群众体育与竞技体育的联系;为提高运动员的训练质量,提高文化考核的地位势在必行;俱乐部体制虽然与现阶段的我国国情不相适应,但是促进家庭与俱乐部的沟通联系,能为运动员学生营造更佳的体育活动环境;根据地区差异,应因地制宜、多元投资,为竞技体育的发展提供依据。     

Anthropometric and physical performance characteristics of top-elite,elite and non-elite youth female team handball players

In order to maximise the potential for success, developing nations need to produce superior systems to identify and develop talent, which requires comprehensive and up-to-date values on elite players. This study examined the anthropometric and physical characteristics of youth female team handball players (16.07 ± 1.30 years) in non-elite (n = 47), elite (n = 37) and top-elite players (n = 29). Anthropometric profiling included sum of eight skinfolds, body mass, stature, girths, breadths and somatotype. Performance tests included 20 m sprint, counter-movement jump, throwing velocity, repeated shuttle sprint and jump ability test, and Yo-Yo Intermittent Recovery Test Level 1. Youth top-elite players had greater body mass, lean mass, stature, limb girths and breadths than elite and non-elite players, while only stature and flexed arm were higher in elite compared to non-elite players (all P < 0.05). Sum of skinfolds and waist-to-hip ratio were similar between groups (P > 0.05). Top-elite performed better in most performance tests compared to both elite and non-elite players (P < 0.05), although maximal and repeated 10 m sprints were similar between playing standards (P > 0.05). Elite outperformed non-elite players only in throwing velocity. The findings reveal that non-elite players compare unfavourably to top-elite international European players in many anthropometric and performance characteristics, and differ in a few characteristics compared to elite European club team players. This study is useful for emerging team handball nations in improving talent identification processes.     

运动竞赛中"瓦伦达心态"现象的成因及其控制路径

从研究瓦伦达心态出发,阐述了瓦伦达心态的理论内涵,并把其引入运动竞赛之中,分析在各种运动竞赛中运动员出现的瓦伦达心态现象,进一步找出运动员在竞赛中出现"瓦伦达心态"现象的成因:即内在因素和外在因素.并有针对性地提出一些控制这种现象出现的路径,试图为运动员参加运动竞赛提供一些理论参考.     

中国高校与全美大学生体育联合会竞技体育人才培养比较

对我国高校与全美大学生体育联合会竞技体育人才培养进行比较分析。研究认为在追求一致的人才培养目标的前提下,全美大学生体育联合会竞技体育人才培养的制度,较之我国高校更加全面、精细;运行机制更完善和科学合理;实际人才产出效果更加显著。建议突出大学生体育协会的独立法人地位;集优整合目前松散的体教结合制度建设;建立一套以人为本理念下的规则章程。     

我国社会体育指导员的特点研究

采用文献资料、问卷调查、访谈等研究方法,对社会体育指导员的数量、分布领域、学历等进行研究,探讨目前社会体育指导员的特点。研究发现,我国社会体育指导员具有如下特点:①数量不足,区域发展不均衡;学历层次低,非体育专业比例大。②我国社会体育指导员的劳动性质以无偿服务为主;工作环境以非体育场所居多;指导时段多为余暇时间。     

自由教育理念与职业体育价值观的互动与融合--美国竞技体育人才培养模式的文化基因

当今世界竞技体育水平最高的国家当属美国。有效的人才培养体制是美国竞技体育兴旺发达的根本保证。任何一种竞技体育人才培养模式的形成都不是偶然的，它必然植根于某种教育理念或化价值观。正是由于自由教育理念与职业体育价值观的长期互动与融合，才形成了当今独具美国特色的竞技体育人才培养模式。竞技体育人才培养是一项系统工程，要根据本国化传统与体育价值取向选择合理的培养模式，不要盲目攀比或简单复制。     

特长班教学对高校体育人才培养的影响

运用文献资料法、问卷调查法、定量分析法、数理统计法等,对大连外国语大学体育特长班教学内容适应程度和人才培养效果进行分析,提出了通过体育特长班培养学生体育人才,提高学生的综合素质,培养全面发展人才的新模式。