Progression and variability of competitive performance of Olympic swimmers

Estimates of progression and variability of athletic performance in competitions are useful for researchers and practitioners interested in factors that affect performance. We used repeated-measures mixed modelling to analyse 676 official race times of 26 US and 25 Australian Olympic swimmers in the 12-month period leading up to the 2000 Olympic Games. Progression was expressed as percent changes in mean performance; variability was expressed as the coefficient of variation in performance of an individual swimmer between races. Within competitions, both nations showed similar improvements in mean time from heats through finals (overall 1.2%; 95% confidence limits 1.1 to 1.3%). Mean competition time also improved over 12 months by a similar amount in both nations (0.9%; 95% confidence limits 0.6 to 1.2%). The US swimmers showed a greater improvement between the finals (a difference of 0.5%; 95% confidence limits ?0.2 to 1.1%), which paralleled changes in the medal haul of the two nations. The coefficient of variation in performance time for a swimmer between races was 0.60% (95% confidence limits 0.56 to 0.65%) within a competition and 0.80% (95% confidence limits 0.73 to 0.86%) between competitions. Our results show that: (a) to stay in contention for a medal, an Olympic swimmer should improve his or her performance by ～1% within a competition and by ～1% within the year leading up to the Olympics; (b) an additional enhancement of ～0.4% (one-half the between-competition variability) would substantially increase the swimmer's chances of a medal.     

优秀田径运动员奥运周期竞技状态变化特征研究

在竞技极值化和多赛制的背景下,优秀田径运动员奥运周期竞技状态变化愈加复杂,而把握不同项目奥运周期竞技状态的变化趋势有利于实现获得理想奥运成绩这一目标。统计发现,在4种基本类型中,除投掷类波动型所占比例大于平稳型外,其余各类项目均表现为上升型>平稳型>波动型>下降型。其中,平稳型中除超长类,其余5类项目均保持年度内状态的稳定;在上升型中的第1年成绩较低、稳定性较高,状态升高可以在之后的任意一年出现,且第4年稳定性较低;下降型主要在投掷类中出现,年内状态的稳定性与成绩水平相反;波动型中绝大多数在第2或第3年出现竞技状态低谷,第4年成绩较好但稳定性较低。总体而言,投掷类项目的变化类型最多,结构也最为复杂,对教练员和运动员的竞技状态调控能力和艺术提出了更高的要求,其后依次为跳跃类、短跨类、全能类、中长类和超长类。     

北京2008奥运会中国女子中长跑队展望

运用文献资料法对当今世界女子中长跑的比赛特点和训练发展趋势进行对比分析,认为当今女子中长跑的比赛是两头快中间稍慢的速度节奏特点,训练发展趋势是以速度为核心的大强度训练。我国女子中长跑运动员在比赛速度节奏的把握和最后的冲刺速度能力上与国外运动员有一定的差距,与此同时也为我国女子中长跑今后的训练提出了合理性建议。     

Muscle morphology of the vastus lateralis is strongly related to ergometer performance,sprint capacity and endurance capacity in Olympic rowers

Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates to rowing ergometer performance, sprint and endurance capacity of Olympic rowers. Eighteen rowers (12♂, 6♀, who competed at 2016 Olympics) performed an incremental rowing test to obtain maximal oxygen consumption, reflecting endurance capacity. Sprint capacity was assessed by Wingate cycling peak power. M. vastus lateralis morphology (volume, physiological cross-sectional area, fascicle length and pennation angle) was derived from 3-dimensional ultrasound imaging. Thirteen rowers (7♂, 6♀) completed a 2000-m rowing ergometer time trial. Muscle volume largely explained variance in 2000-m rowing performance (R² = 0.85), maximal oxygen consumption (R² = 0.65), and Wingate peak power (R² = 0.82). When normalized for differences in body size, maximal oxygen consumption and Wingate peak power were negatively related in males (r = ?0.94). Fascicle length, not physiological cross-sectional area, attributed to normalized peak power. In conclusion, vastus lateralis volume largely explains variance in rowing ergometer performance, sprint and endurance capacity. For a high normalized sprint capacity, athletes may benefit from long fascicles rather than a large physiological cross-sectional area.     

影响中国女性运动员在奥运会创造优异运动成绩的因素分析

北京奥运会能否成功,很大程度上取决于运动员取得的成绩,而女运动员的表现至关重要。“举国体制”、经济的高速发展、中国女性体育消费文化、体育商业化可能给我国女性运动员在2008年奥运会创造优异运动成绩带来影响。探讨其因素,有助于让女性运动员了解自身所处的环境,为其能够在2008年奥运会取得优异成绩提供参考。     

备战21届冬奥会我国短道速滑女子优秀运动员膳食营养调查与分析

为促进我国短道速滑队优秀运动员膳食营养水平,并为运动员提供合理、平衡膳食的指导依据,对备战第21届温哥华冬奥会的6名优秀短道速滑运动员进行了膳食营养调查和分析,结果表明：全体运动员均摄入低热能高脂肪食物以利于高原训练,三餐配比符合运动项目的特点,膳食营养基本能满足运动员的日常训练消耗。存在问题主要是运动员维生素A、B1摄入不足,锌摄入量普遍低于推荐值。不足的营养可通过加餐和营养补剂强化。     

我国优秀男子散打运动员身体功能训练研究

探讨身体功能训练在我国优秀男子散打运动员的应用实践效果,采用随机对照实验设计对我国24名优秀男子散打运动员进行为期16周、每周3次、每次60 min的身体功能训练。结果显示:(1)在基本运动能力方面,实验组在平板支撑、仰卧脚撑瑞士球平板支撑、悬吊侧卧平板支撑(左和右两侧)、单腿站平衡垫、瑞士球静蹲、坐位体前屈7项指标上较对照组有非常显著性改善(P<0.01);(2)在一般运动能力方面,实验组在400 m跑、单足4级跳、立卧撑3项指标上较对照组有显著性提高(P<0.05),在Illinois跑、高翻、卧推、深蹲等4项指标上较对照组有非常显著性提升(P<0.01);(3)在专项运动能力方面,实验组在10 s冲拳、10 s侧踹2项指标上较对照组有显著性提高(P<0.05),在30 s变向击打靶、30 s夹背摔假人、单次鞭腿击打力量、10 s腿法击打力量、10 s拳腿组合击打力量5项指标上较对照组有非常显著性提升(P<0.01)。结果表明:优秀男子散打运动员实验组的身体功能训练方案相对于对照组传统力量训练方案,强化了运动员的核心稳定性,优化了动作模式,加强了核心力量及其传输效率,对发展散打运动员的身体功能效果更佳。     

对我国优秀女子铁饼运动员肩、髋动作特征的研究

运用爱捷运动录像三维测量分析系统对我国优秀女子铁饼运动员的肩和髋的动作进行了三维运动学分析。结果表明 :左脚离地时的身体姿势对腾空、过渡阶段和最后用力阶段有着重要的影响 ;在最后用力阶段 ,拉引角数值的增量制约着铁饼运行的距离 ;我国运动员与世界优秀运动员的主要差距在过渡阶段。存在的问题 :运动员没能有效地做出右脚的转扣着地及着地后不停顿的旋转动作 ;左髋带动左大腿促使左脚尽快摆压动作过慢。     

中国优秀男子柔道运动员身体成分特征及与无氧代谢能力关系的研究

目的：探讨我国优秀男子柔道运动员身体成分特征及与无氧代谢能力的关系。方法：以中国国家男子柔道队59名优秀运动员为研究对象．采用InBody3．0多频分段生物电阻抗身体成分测试仪（韩国Biospace公司）进行身体成分的测定，采用30s Wingate测定无氧代谢能力。结果：我国优秀男子柔道运动员身体成分特点为低体脂率，高瘦体重；体脂百分比、瘦体重和肌肉重量等指标表现出明显的体重级别特征；与拳击、跆拳道、摔跤等项目运动员相比，体脂百分比较低，瘦体重，体重、肌肉重量，体重比值较高。同时，健将运动员肌肉的爆发力和速度耐力均优于一级运动员；体重、瘦体重、肌肉重量和蛋白总量都与PP、AP和Pd呈高度正相关，同时肌肉重量与PP和AP表现出更高的相关性。结论：我国优秀男子柔道运动员身体成分具有明显的项目特征，同时运动员的最大做功和运动能力与肌肉的体积关系密切。     

Strapping rowers to their sliding seat improves performance during the start of ergometer rowing

Abstract

Rowers sit on a seat that slides relative to the boat/ergometer. If a rower lifts him or herself from this sliding seat at any time, the seat will move away from under them and the rowing action is disrupted. From a mechanical perspective, it is clear that the need for the rower to remain in contact with the sliding seat at all times imposes position-dependent constraints on the forces exerted at the oar handle and the footstretcher. Here we investigate if the mechanical power output during rowing, which is strongly related to these forces, might be improved if the contact with the sliding seat was of no concern to the rower. In particular, we examine if elimination of these constraints by strapping the rower to the sliding seat leads to an increase in performance during the start on a standard rowing ergometer. Eleven well-trained female rowers performed 5-stroke starts in normal and strapped conditions. Handle force, vertical seat force, footstretcher force, and handle kinematics were recorded, from which mechanical power and work output were calculated. Most of the relevant mechanical variables differed significantly between the normal and strapped conditions. Most importantly, mechanical power output (averaged over the 5-stroke start) in the strapped condition was 12% higher than in the normal condition. We conclude that strapping a rower's pelvis to the sliding seat allows more vigorous execution of the stroke phases, resulting in a substantial improvement in performance during the start of ergometer rowing.     

Reliability of lower limb biomechanics in two sport-specific sidestep cutting tasks

The purpose of this study was to assess the within- and between-session reliability of lower limb biomechanics in two sport-specific sidestep cutting tasks performed by elite female handball and football (soccer) athletes. Moreover, we aimed at determining the minimum number of trials necessary to obtain a reliable measure. Nineteen elite female handball and 22 elite female football (soccer) athletes (M ± SD: 22 ± 4 yrs old, 168 ± 5 cm, 66 ± 8 kg) were tested. The reliability was quantified by intra-class correlations (ICCs), typical error and Spearman’s rank correlation. Only minor improvements in ICC values were seen when increasing the number of trials from 3 to 5. Based on trials 1–3, all variables showed good to excellent within-session reliability (M ICC: 0.91, 95% CI: 0.89–0.93), fair to good between-session reliability (M ICC: 0.73, 95% CI: 0.70–0.76), moderately positive between-session rank correlation coefficients (M: 0.72, 95% CI: 0.69–0.76). A few frontal plane biomechanical variables displayed lower between-session reliability in the football task compared with the handball task. The moderately positive between-session ranking and practically small typical error implies that the measurements could reliably reproduce the ranking of individuals in multiple-session studies. Adequate reliability could be attained from 3 trials, with only minor improvements when adding more trials.     

Strapping rowers to their sliding seat improves performance during the start of single-scull rowing

In this study, the effect of strapping rowers to their sliding seat on performance during 75 m on-water starting trials was investigated. Well-trained rowers performed 75 m maximum-effort starts using an instrumented single scull equipped with a redesigned sliding seat system, both under normal conditions and while strapped to the sliding seat. Strapping rowers to their sliding seat resulted in a 0.45 s lead after 75 m, corresponding to an increase in average boat velocity of about 2.5%. Corresponding effect sizes were large. No significant changes were observed in general stroke cycle characteristics. No indications of additional boat heaving and pitching under strapped conditions were found. The increase in boat velocity is estimated to correspond to an increase in average mechanical power output during the start of on-water rowing between 5% and 10%, which is substantial but smaller than the 12% increase found in a previous study on ergometer starting. We conclude that, after a very short period of adaptation to the strapped condition, single-scull starting performance is substantially improved when the rower is strapped to the sliding seat.     

我国空中技巧男队备战第21届冬奥会的形势与对策初探

采用文献资料、调查访问、现场观察与录像观察等方法,分析我国自由式滑雪空中技巧男队备战第21届冬奥会的形势,探讨由此应采取的相应对策。结果得出:目前我队动作难度处于第2档次,整体实力排在第3位,2010年温哥华冬奥会将面临一场艰难的卫冕之战;为了届时再铸辉煌,我国男选手应紧紧跟上世界潮流,大力发展第二周含tF的高难动作,并高度重视后备力量的培养。     

陈艳青备战北京奥运会专项辅助练习与竞赛成绩关系研究

采用文献资料、数理统计等方法,研究2004年雅典和2008年北京两届奥运会女子举重58公斤级冠军陈艳青在备战北京奥运会期间的主要辅助练习和竞赛成绩之间的关系。结果显示:主要专项辅助动作成绩与竞赛动作成绩具高度显著性相关;宽拉、后蹲成绩共同作用影响抓举成绩;借力推、高翻混挺、垫木窄硬拉成绩共同作用影响挺举成绩;陈艳青在训练内容的选择上有其明显的特点。     

我国优秀青年蹼泳运动员心理运动能力的评价与培养的研究

从运动心理学方面对我国优秀青年蹼泳运动员心理运动能力进行研究，通过与我国优秀蹼泳运动员心理运动能力的比较，发现青年运动员与成年运动员在心理运动能力方面无显性差异，认为青年运动员心理运动能力的高水平发展与较早接受专项运动训练密切相关，运动员赛前心境状况较差且不稳定，女运动员表现更为突出，建议在青年蹼泳运动员选材时，要注意运动员的心理特征和规律。     

2008年奥运会拳击比赛中哈那提的数据统计及技术分析

采用平面定点摄像、录像解析和数据统计等方法,对新疆重点运动员哈那提·斯拉木在2008年奥运会69kg级比赛中的技术动作进行数据统计和比对分析,找出其战术动作上的不足之处,并提出相应的对策。     

中外优秀田径运动员竞技年龄特征之比较研究

运用文献资料调研和数理统计法，对当今世界与中国优秀田径运动员在亚类项群、亚类分组项目的竞技年龄结构特征进行比较，分析两者之间的差异，旨在为我国田径项目多年训练过程的合理规划提供理论依据.     

LoLo、HiLo、LoHi和HiHiLo训练过程中血象指标变化规律的比较研究

采用实验法，将24名优秀女子赛艇运动员分为4组（每组6人），分别进行4周低住低练（LoLo）、高住低练（HiLo）、低住高练（LoHi）和高住高练低练（HiHiLo），旨在探讨不同模式低氧训练过程中运动员血象指标RBC、Hb、Hct和WBC动态变化的规律和特点。结论认为：不同模式低氧训练中RBC、Hb和Hct的变化幅度、特点与规律存在一定差异，与高原训练比较也有所不同；HiLo、LoHi和HiHiLo3种低氧训练模式均能明显提高运动员的RBC、Hb和Hct，但不同模式提高程度不同，RBC表现为HiLo〉HiHiLo〉LoHi〉LoLo，HB和Hct表现为HiHiLo〉HiLo〉LoHi〉LoLo，RBC与Hb和Hct的增加不完全同步；4周3种模式低氧训练效果至少可以保持2周，而HiHiLo组训练后保持Hb的能力要优于HiLo和LoHi组；不同低氧训练模式虽对WBC造成一定规律性的改变，但各组间无明显差异的结果表明，不同低氧训练模式对机体免疫机能虽有影响，但不明显。     

优秀田径运动员心率变异性分析

目的:分析优秀田径运动员心率变异性(HRV)特征,为HRV在运动员选材、机能评定等应用提供理论依据。方法:选取江苏省专业运动队优秀田径运动员和普通健康人各25名进行连续5min心电图时域和频域记录获得HRV指标,以普通健康人为对照分析优秀田径运动员HRV特征。结果:(1)女运动员VLF低于男运动员(P<0.05),其余指标无性别差异。(2)优秀田径运动员SDNN、RMSSD、PNN50、TP、HF、VLF均高于普通健康人(P<0.05或P<0.01);LF、LF/HF二者无差异(P>0.05)。结论:(1)优秀田径运动员自主神经活性和迷走神经的紧张性没有性别差异,安静时男性运动员拥有较高的交感神经张力。(2)优秀田径运动员安静时比普通健康人拥有更强的心脏自主神经活性、更高的迷走神经紧张性和交感神经兴奋性,迷走和交感神经均衡性无差异。     

中外优秀男子铁饼运动员身体素质指标的比较分析

采用关联分析方法,对我国8名优秀男子铁饼运动员的7项身体素质指标进行综合分析,找出各项身体素质指标对运动成绩影响的主次关系;并与国外优秀男子铁饼运动员进行比较,从中发现我国男子铁饼运动员身体训练中的不足,并对今后的训练提出了建议。