Electromyographic analysis of thigh muscles during track cycling on a velodrome

We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles.     

The understanding and development of cycling aerodynamics

In elite cycling the resistive force is dominated by aerodynamics. Be it on the roads or in the velodrome, the sport has many examples where aerodynamics has won and lost races. Since the invention of the bicycle, engineers have strived to improve performance, often by reducing aerodynamic drag. Over the last 50 years a number of authors have presented their efforts in journals, books and magazines. This review summarises the publications that show the continued development in the aerodynamics of cycling. The review concludes by examining the shortcomings of the current understanding and making suggestions for future research and development.     

Determining optimal pacing strategy for the track cycling individual pursuit event with a fixed energy mathematical model

Competitive track cycling races are won by milliseconds, and the regulation of an athlete’s power output is an important factor in performance. The aim of this study was to use a mathematical model to predict finishing times for different pacing strategies for the individual pursuit (IP), to identify the optimal strategy in terms of fastest finishing time. Power profiles were generated for a number of common pacing strategies used in cycling, which were based on actual SRM power data for an elite, male, IP cyclist for whom the average power, maximum power, total work done and actual finishing time were known. The total work output was the same for all strategies and the finishing time was predicted using a mathematical model developed previously. The results showed that, of the strategies tested, an initial “all-out” high power acceleration phase followed by a lower constant power output produced the fastest finishing time for a 4,000 m IP event, and that the time spent in the initial high power acceleration phase had a significant effect on performance.     

Success in elite cycling: A prospective and retrospective analysis of race results

The development of peak performances is a main research focus in sports science. It is unclear how many former top junior athletes achieve success in the elite class later. The aim of the present study was to examine the careers of athletes who participated in major junior or adult/elite cycling events using prospective and retrospective analysis of competition results. The official results of major junior (age < or = 18 years) and elite (age > 18 years) cycling races from 1980 to 2004 were analysed. Age-related aspects, career lengths, and success were compared between riders who presented results in both junior and elite races (JUNIOR ELITE) and riders who had no junior race results (ELITE ONLY). Altogether, 27,454 results of 8004 athletes from 108 countries were collected. We found that 29.4% of the elite athletes had participated in junior World Championships, and that 34% of the participants in junior World Championships later participated in major elite competitions. JUNIOR ELITE athletes are significantly more successful in several cycling disciplines and have their first and last elite result at a younger age than ELITE ONLY athletes. No difference was found in career lengths. The data presented here emphasize the importance of long-term training programmes in the development of peak performance in cycling.     

Success in elite cycling: A prospective and retrospective analysis of race results

Abstract

The development of peak performances is a main research focus in sports science. It is unclear how many former top junior athletes achieve success in the elite class later. The aim of the present study was to examine the careers of athletes who participated in major junior or adult/elite cycling events using prospective and retrospective analysis of competition results. The official results of major junior (age ≤ 18 years) and elite (age > 18 years) cycling races from 1980 to 2004 were analysed. Age-related aspects, career lengths, and success were compared between riders who presented results in both junior and elite races (JUNIOR ELITE) and riders who had no junior race results (ELITE ONLY). Altogether, 27,454 results of 8004 athletes from 108 countries were collected. We found that 29.4% of the elite athletes had participated in junior World Championships, and that 34% of the participants in junior World Championships later participated in major elite competitions. JUNIOR ELITE athletes are significantly more successful in several cycling disciplines and have their first and last elite result at a younger age than ELITE ONLY athletes. No difference was found in career lengths. The data presented here emphasize the importance of long-term training programmes in the development of peak performance in cycling.     

男子二级跳远运动员起跳阶段摆动腿技术的运动学分析

文章运用文献资料、数理统计和图像解析的研究方法,对二级跳远运动员的运动学指标进行研究。结果表明：（1）二级运动员起跳时间平均值是0.130s,缓冲时间平均值为0.048s,蹬伸时间平均值0.082s。缓冲时间、蹬伸时间与整个起跳时间过长。这与二级运动员本身身体素质和技术动作的优劣存在很大关系;（2）二级运动员着板瞬间,摆动腿的摆动角速度平均值为451.72°/s,膝关节角度平均为87.14°上板速度为8.58m/s,与前人的研究有出入;（3）二级运动员速度利用率为76.30%,速度利用率明显低于优秀运动的速度利用率。腾起角平均为26.66°,明显高于优秀运动员的18°-25°;（4）在蹬伸阶段摆动角速度的最大值与腾起角和成绩明显正相关。     

我国优秀女子摔跤运动员体能特点的研究

为了解我国优秀女子摔跤运动员体能特点,采用调查、测试和数理统计方法对我国53名优秀女子摔跤运动员体能结构指标进行测试与分析。结果表明:(1)优秀女子摔跤运动员在身体形态上发生良好的适应性变化,具体表现为身材、身体充实度和去脂体重较高,体脂含量较低;(2)优秀女子摔跤运动员磷酸原供能能力较好,心血管系统机能良好,并具备较强的有氧代谢能力,但糖酵解供能能力有待加强;(3)不同级别选手运动素质方面表现出较大的差异性,具体表现为在最大力量方面大级别运动员优势明显,而在速度、灵敏、耐力方面中小级别运动员则具备较大的优势。     

从国外运动员的投掷特征看我国优秀女子链球选手的投掷技术

对我国5名优秀女子链球运动员使用近景动态三维录像分析系统分析运动员的投掷技术,结果表明,第四圈双支撑阶段加速能力较强,但在第四圈单支撑阶段速度损失过大;链球旋转速度增量与各圈轨迹中双支撑与单支撑的比值有关,增大链球各圈轨迹中双支撑与单支撑的比值有助于链球旋转速度增量的提高;加大投掷动作的动作幅度,增大各圈旋转中运动员的各运动环节的最大值与最小值的差值对链球旋转速度增量的提高具有十分重要意义。     

我国优秀男子龙舟运动员身体素质评价模型的研究

运用文献资料法,数理统计法,专家访谈法等多种研究方法,对2009年全国龙舟锦标赛、中华龙舟大赛总决赛、2010年亚运会全国选拔赛中各单项前六名的30支优秀男子龙舟队伍的运动员身体素质指标进行研究,通过研究分析,确立我国优秀男子龙舟运动员身体素质的评价模型。结果表明:1)我国优秀男子龙舟运动员的身体素质主要由力量、耐力、柔韧、速度、灵敏5个因子构成,其中力量因子和耐力因子的载荷贡献率较大。2)我国优秀男子龙舟运动员的身体素质特征表现为:力量较大,速度快,耐力突出,反应灵敏,柔韧性很好等特点。3)根据各素质指标测得数据统计分析,按其的权重比例构建评价体系模型,为我国优秀男子龙舟运动员的科学选材和训练提供重要的参考依据。     

我国优秀男子1500m运动员各段落途中跑运动学特征研究

利用高速录像拍摄法、比较分析法、数理统计法等对参加2004年全国田径冠军赛暨大奖赛总决赛合肥站的我国优秀男子1500m运动员各段落途中跑的运动学特征进行了专题研究。结果表明:我国优秀男子1500m运动员各段落途中跑的运动学特征存在明显变形,主要表现在第二、三圈的平均速度明显低于第一、四圈的平均速度,这主要是由于我国优秀男子1500m运动员在第二、三圈支撑腿的缓冲时间延长、后蹬时间缩短所造成。     

优秀自由泳运动员分段时间的特征研究

对近4届世界游泳锦标赛上高水平(决赛和半决赛)自由泳运动员的运动成绩进行分析,其中男、女各224人共历时7年.通过各分段时间与最终成绩的相关分析,以及历届不同水平、性别的优秀运动员在各个项目上的分段时间进行研究.结果发现,在任何项目上,不论水平高低,自由泳运动员都呈现较为类似的时间分配模式,其中在短距离项目上,水平越高的运动员前后半程的分段时间差越小并趋于均衡;在中距离项目上,男子运动员后半程保持速度的能力优于女子,历届世锦赛的获胜者在每个分段上处于领先位置,尤其在途中的游速上;同时长距离项目上水平较高的运动员在途中的分段时间有明显的下降趋势(加速)且变化较小,而水平稍差的运动员有明显的上升趋势(减速).建议教练员和运动员在保持总分段时间分配特征的前提下,通过技术优化和力量训练来提高分段成绩,进一步提高比赛成绩.     

场地自行车在直弯道之间的速度波动研究

用5台德国产自行车数据收集分析系统(SRM自行车仪),收集、处理在南京、深圳、昆明等场地自行车训练和比赛的生物力学数据,按照不同场地,不同骑行速度计算人车系统在进出直弯道时平均速度和最大速度的变化。结果表明:速度波动与场地半径有显著性关系。当自行车从直道进入弯道时速度增加,而自行车从弯道进入直道时速度减小。250m场地上的速度波动比333.3m场地更大。速度波动与运动员骑行速度没有显著性关系。     

场地自行车男子运动员机体反馈指标6年追踪研究

目的:研究以浙江省场地自行车短距离项目男子运动员为研究对象,通过六年的训练负荷反馈指标和机能反馈指标的采集、测试和分析,探讨上述指标对我省场地自行车短距离项目男子运动员成长存在的影响,为我省场地自行车男子短距离项目的持续高效的发展提供一定的理论依据。方法:在六年的训练周期中,对我省自行车运动员的血红蛋白、血清睾酮、血清肌酸激酶和血尿素氮进行定期测试,并形成比较完整的数据库进行对比分析。结果:①优秀组和普通组的血清睾酮、血清肌酸激酶和血尿素氮6年间变化趋势基本一致,而血红蛋白存在不同的变化趋势;②在机能反馈变化方面,与优秀组相比较,普通组的血红蛋白平均值在2012年、2016年和2017年有非常显著性差异(P<0.01),而血清睾酮则在2012年、2013年和2016年存在非常显著性差异(P<0.01);③在训练负荷反馈方面,仅在2017年,优秀组的血清肌酸激酶平均值与普通组相比较,出现非常显著性差异(P<0.01)。结论:①对场地自行车短距离男子运动员来说,血红蛋白在训练初期可能不是最主要的机能指标,但是到训练中后期可能会成为评价运动员恢复能力的一项主要指标;②血清睾酮水平的高低对场地自行车短距离男子运动员的成才至关重要,是训练初期就需要重点关注的一个指标;③血清肌酸激酶和血尿素氮分别是训练强度和训练量的机体反馈指标,优秀运动员在训练内容转换的过程中,适应能力要好于普通运动员。     

Tour de France,Giro, Vuelta,and classic European races show a unique progression of road cycling speed in the last 20 years

Abstract

Road cycling ranks among the most intense endurance exercises. Previous studies and mathematical models describing road cycling have not analysed performances per se. We describe the evolution of road cycling performance over the past 116 years. We studied the top ten cyclists' mean speeds in eight famous classic races and three European Grand Tours, using a previously published multi-exponential model that highlights the different progression periods of an event during the century. In addition, we measured an indicator of difficulty for the Tour de France by calculating the climbing index (i.e. the total altitude climbed over total distance). The eleven races' mean speed increased progressively from 23.13 km · h^?1 in 1892 to 41.19 ± 2.03 km · h^?1 in 2008. Road cycling development, like other quantifiable disciplines, fits a piecewise progression pattern that follows three periods: before, between, and after the two World Wars. However, a fourth period begins after 1993, providing a speed progression of 6.38% from the third one. The Tour de France's climbing index also provided insight into a recent paradoxical relationship with speeds: when the climbing index increased, the winner's speed also increased. Our results show a major improvement (6.38%) in road cycling performance in the last 20 years and question the role of extra-physiological parameters in this recent progression.     

Performance determinants of fixed gear cycling during criteriums

Nowadays, fixed gear competitions on outdoor circuits such as criteriums are regularly organized worldwide. To date, no study has investigated this alternative form of cycling. The purpose of the present study was to examine fixed gear performance indexes and to characterize physiological determinants of fixed gear cyclists. This study was carried out in two parts. Part 1 (n?=?36) examined correlations between performance indexes obtained during a real fixed gear criterium (time trial, fastest laps, averaged lap time during races, fatigue indexes) and during a sprint track time trial. Part 2 (n?=?9) examined correlations between the recorded performance indexes and some aerobic and anaerobic performance outputs (VO_2max, maximal aerobic power, knee extensor and knee flexor maximal voluntary torque, vertical jump height and performance during a modified Wingate test). Results from Part 1 indicated significant correlations between fixed gear final performance (i.e. average lap time during the finals) and single lap time (time trial, fastest lap during races and sprint track time trial). In addition, results from Part 2 revealed significant correlations between fixed gear performance and aerobic indicators (VO_2max and maximal aerobic power). However, no significant relationship was obtained between fixed gear cycling and anaerobic qualities such as strength. Similarly to traditional cycling disciplines, we concluded that fixed gear cycling is mainly limited by aerobic capacity, particularly criteriums final performance. However, specific skills including technical competency should be considered.     

世界优秀短道速滑运动员500m滑行轨迹的运动学研究

目的：通过对现场采集的短道速滑500 m项目的优秀运动员运动视频进行处理,获取相关运动学参数,揭示优秀短道速滑运动员滑行运动学参数特征,为运动员科学训练提供依据。方法：通过单台摄像机定点拍摄获取比赛录像,无须在现场放置框架,利用冰面现有文字和线段进行摄像机空间标定,利用SIMImotion解析软件得到运动员滑行轨迹的像坐标,最后通过射影变换原理获取运动员在冰面上的滑行轨迹等运动学指标。结果：数据显示在第三圈男女平均速度都达到最大,男子最大圈平均速度为14.14 m/s,女子为13.07 m/s。男女直道平均速度、弯道平均速度、入弯瞬时速度和出弯瞬时速度都在第5次达到最大值。男子直道最大平均速度为14.13 m/s,女子为13.13 m/s;男子弯道最大平均速度为14.70 m/s,女子为13.51 m/s;男子入弯最大瞬时速度为14.76 m/s,女子为13.66 m/s;男子出弯道最大瞬时速度为14.21 m/s,女子为13.12 m/s。起跑到第8步时,男女瞬时速度分别达到了8.39 m/s和7.63 m/s,男女步长分别达到2.98 m和2.44 m。结论：(1)利用射影变换原理完成运动员比赛滑行路线的标定,为短道速滑研究提供了一种新方法。(2)优秀短道速滑运动员在500 m滑行中弯道速度贡献大于直道,起跑爆发力对抢位战术影响较大,运动员体能情况对最后两圈影响较大。     

广州亚运会20km竞走运动员速度变化特征

采用数理统计法,对2010年广州亚运会上男子20km、女子20km优秀竞走选手的速度特征进行研究。结果表明：在20 km竞走比赛的最后阶段,大多数男子选手的速度呈下降趋势,获得前3名的女子选手的速度也呈下降趋势。优秀男子20km选手的最低平均速度出现在12~14km段,最高平均速度出现在14~16km段;获得前3名的女子运动员最低平均速度出现在18~20km段,最高平均速度出现在8~10km段;男子各段速度起伏较大,女子各段平均速度起伏较小。     

我国优秀游泳运动员速度耐力专项素质综合评价研究

以我国优秀游泳运动员为研究对象，以速度、耐力专项素质为研究内容，通过文献资料和数理统计方法，在赋予各指标以不同权重基础上，对我国优秀游泳运动员的速度耐力专项素质给予科学的评价，结果表明，在反映我国优秀运动员速度耐力专项素质的整体信息中，各指标权重差异不大。相对而言，以75m自由泳、200m和400m混合泳专项素质所占的权重较大。另外，按照百分法制定的我国优秀游泳运动员专项素质评价标准是科学的，也是可行的，该评价标准，不仅适应于对我国优秀运动员速度耐力专项素质的评价，同时也为评价其他水平运动员专项素质水平提供了一个理想的标准模式。     

对中外优秀十项全能运动员比赛成绩的灰色协调分析

男子十项全能是一项复杂的综合性竞技项目，也是一个典型的灰色系统。运用GM（1，N）动态协调模型对国内外全能选手在总成绩不断提高的各个阶段中各因素间相互联系，相互影响的辩证发展关系进行多方位、多层次的分析，揭示了身体素质中速度与力量这对主要矛盾因素的互相促进和制约是十项全能水平不断提高与发展的关键，同时也揭示了速度与力量的发展失衡是我国男子十项全能选手成绩徘徊不前的主要原因。     

我国优秀男女蹦床运动员竞技水平与成绩变化特征研究

蹦床是2000年悉尼奥运会和“九运会”新设比赛项目。采用比赛现场裁判评定、调研考察、文献研究等方法,从规定动作和自选动作的技术分、难度值、成功率几个方面,对我国优秀男女蹦床运动员的比赛状况、竞技水平和成绩名次进行了研究。结果表明：男子运动员规定动作的稳定性和动作质量明显强于女子;男女运动员自选动作成绩的提高表现出增长方式的不一致性;女子尖子选手主要在动作质量上优于女子平均水平,而男子尖子选手在动作难度、动作质量两方面均明显高于男子平均水平。