Russians are the fastest and the youngest in the “Comrades Marathon”     

Pantelis T. Nikolaidis 《Journal of sports sciences》2019,37(12):1387-1392

The present retrospective study intended to determine age, performance, the role of nationality and participation trends across calendar years in runners competing in “Comrades Marathon”, the ultra-marathon with the longest tradition and the highest number of finishers worldwide. We analysed 235,467 finishers (40,211 women and 195,256 men) competing between 1994 and 2017. In women and men, Russians were the fastest (12.55 ± 2.03 km/h and 12.24 ± 2.93 km/h, respectively) and Indians the slowest (7.87 ± 0.64 km/h and 7.91 ± 0.60 km/h) (p < 0.001, η2 = 0.053 and η2 = 0.010, small effect size, ES). Also, Russians were the youngest (33.9 ± 4.6 and 36.3 ± 5.9 years, respectively) and Japanese the oldest (49.3 ± 9.6 and 51.4 ± 12.3 years, respectively) (p < 0.001, η2 = 0.011, small ES). Performance improved (r = 0.90 in women and r = 0.92 in men), age of finishers (r = 0.91 in women and r = 0.97 in men), participation (r = 0.92 in women and r = 0.87 in men) and sex difference in age increased (r = 0.71), whereas men-to-women ratio (r = ?0.91) and sex difference in performance (r = ?0.68) decreased across calendar years (p < 0.001). In summary, runners from Russia were the fastest and the youngest in both sexes. The knowledge of the relationship of nationality with performance, age and participation trends of finishers, and changes across calendar years are of practical importance for ultra-runners and coaches working with them.  相似文献   

草根体育组织规范化发展研究——以我国跑团为例     

王相飞  蔡平原  延怡然 《武汉体育学院学报》2019,53(9):28-34

以我国草根组织中的典型组织——跑团为例,分析了我国跑团兴起的主要原因,发展过程中存在的问题：跑团内部机制不健全,治理方式滞后;缺乏稳定的社会资源;政府职能部门引导、扶持不力;相关的规章制度、法律不够完善;较难获得合法身份致使发展受阻,缺少主管单位监督和行业自律;跑团存在多种安全隐患;对于各种跑团社交软件及社交平台的管理不够。据此提出了对策：对跑团进行分级分类管理,充分发挥中国田协的指导与监督作用,政府部门不断完善跑步公共服务体系,加强跑团制度建设与规范管理,健全安全健康监管保障体系。  相似文献   

Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist     

Johannes Funken  Kai Heinrich  Steffen Willwacher  Ralf Müller  Jonas Böcker  Hiroaki Hobara 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):75-87

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.  相似文献   

The biomechanical characteristics of high-performance endurance running     

Stephen J. Preece  Christopher Bramah  Duncan Mason 《European Journal of Sport Science》2019,19(6):784-792

The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s^?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact.  相似文献   

Effect of different loading conditions on running mechanics at different velocities     

Germán Carretero-Navarro  Doménico Cherubini  Wolfgang Taube 《European Journal of Sport Science》2019,19(5):595-602

Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics.  相似文献   

Nanocontainer aqueous systems for removing polymeric materials from marble surfaces: A new and promising tool in cultural heritage conservation     

Scilla Grassi  Monica Favaro  Patrizia Tomasin  Luigi Dei   《Journal of Cultural Heritage》2009,10(3):347-355

The present study dealt with the characterisation of marble surfaces coated by three kinds of polymeric material usually employed in stones conservation and with the evaluation of the removal of these coatings from the surfaces by means of new nanocontainer aqueous systems constituted of micellar solutions (MS) and oil-in-water microemulsions (MC). The polymeric coatings were also subjected to accelerated artificial ageing in order to detect possible effects associated to natural photochemical ageing. The aim of the work was the assessment of the performance of such nanocontainer aqueous systems taking acetone (Ac) as a reference “traditional” solvent for the removal procedure. The characterisation was carried out by means of Scanning Electron Microscopy (SEM) and Environmental Scanning Electron Microscopy (ESEM), Fourier Transform Infra-Red (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies and the results obtained showed that the performance of these innovative methods based on nanocontainer aqueous systems can be considered highly promising in the view of a “green approach” to the conservation of cultural heritage.  相似文献   

国际化合作办学人才培养模式研究     

杨红 《大连教育学院学报》2014,(1):26-27

大连大学日语专业在学生的国际化、师资、课程、科学研究的国际化及国际拓展五方面开启了国际化合作办学的人才培养模式,并取得了一定的成效。对国际化合作办学人才培养模式改革的研究,能为高校日语专业国际化合作办学的发展提供参考。  相似文献   

中外合作办学与高等农业院校的发展     

张强 《教学研究(河北)》2004,27(1):22-24

本文介绍了我国农业院校与国外合作办学的基本情况,分析了合作办学的重要意义、作用和前景,研究了合作办学的主要模式,针对农业院校中外合作办学中容易出现的问题提出了相应的对策。  相似文献   

论我国一人公司监管存在的问题     

马龙 《山西广播电视大学学报》2010,15(3):74-75

随着全球经济一体化和我国市场经济改革的不断深入,一人公司在我国现实中已广泛存在,由于我国法律的规定不健全,大多数一人公司以一种不规范的模式运行,并衍生出许多问题。鉴于我国现实中已存在大量一人公司的现状,为顺应时代潮流,2005年10月27日第十届全国人大常委会第十八次会议通过了对《公司法》的修订,将一人公司正式写入法律,这无疑成为此次修订的一大亮点。  相似文献   

高职院校特色办学与发展规模之我见     

马琳 《辽宁高职学报》2007,9(4):3-4

处于激烈竞争中的高职院校的发展,规模的扩大和特色的突出是其发展中不可分割的两个方面。突出特色才能保持专业教育上的前瞻性,真正实现高职院校对地方经济的适应和服务职能,但是特色的保持和发展,要有规模的保持和扩展来保证。因此特色的突出与规模的扩大相结合,是高职院校发展中必须树立的理念。  相似文献