对我国优秀男子跳远运动员助跑最后三步步长结构的研究

通过对我国部分优秀男子跳远运动员助跑最后三步离地距离、腾空距离及着地距离的研究,认为运动员助跑最后三步步长结构对助跑水平速度、身体重心高度以及起跳效果都有很大程度的影响;我国男子跳远运动员最后两步步长构成具有不合理性;倒数第二步着地距离过大,最后一步着地距离偏小。前者造成倒数第二步重心高度下降过多、最后一步减速严重、踏板瞬间身体重心水平速度偏低,后者造成起跳过程中垂直作功距离偏短、腾起垂直分速度及腾起角偏低。     

背越式跳高助跑最后一步与起跳效果的关系

1助跑最后一步摆动腿的着地方式对起跳效果的影响 1．1摆动腿着地方式对起跳脚着地时身体重心水平初速度的影响 助跑进入最后一步时摆动腿着地瞬间相对较大的小腿着地角和着地髋角对于保持助跑速度进入起跳是有利的，同时，直接影响人体的水平腾起初速度。这是运动员积极快速正确有效地完成助跑技术动作的结果。而相对较小的小腿着地角和着地髋角是由于运动员在摆动腿着地瞬间有意无意地为起跳做准备而降低重心所造成的，这种方式在摆动腿着地时，就会产生较大的制动，在助跑最后一步摆动腿支撑时期导致水平速度出现过多的损失，从而造成进入起跳阶段时的水平速度及腾起水平速度的下降，严重影响起跳效果。     

跳高运动员郑幸娟倒3步助跑技术分析

对我国优秀女子跳高运动员郑幸娟倒3步助跑技术进行分析,结果表明:郑幸娟倒3步助跑弧线衔接不流畅,导致助跑水平速度的损失;助跑中两臂摆动动作不规范,倒2步摆动腿"牢固支撑"动作做得不够,直接造成身体内倾角加大;倒两步助跑脚着地瞬间身体重心高度出现上升趋势,从而影响了助跑和起跳的衔接;助跑倒1步身体重心水平速度下降明显,起跳脚着地瞬间身体重心水平速度仅为5.94 m/s,比倒2步下降了0.64 m/s,低于国内外优秀女子运动员;助跑倒1步起跳脚着地瞬间身体重心垂直速度为正值,身体重心呈向上运动趋势。郑幸娟跳高的倒3步助跑技术有待改善。     

我国优秀女子背越式跳高运动员助跑最后两步和起跳速度特征的运动学研究

采用技术动作录像、影片分析以及数理统计等方法,通过对我国10名优秀女子跳高运动员助跑最后两步和起跳速度变化特征的运动学分析,提出我国优秀女子跳高运动员最后两步缓冲动作稍大,摆动腿蹬离地面时速度水平较低;大部分运动员身体重心高度波动较大;起跳垂直速度水平与起跳时间有较高的相关性;运动员起跳结束瞬间的垂直速度水平差别较大,但整体水平一般.     

我国部分优秀男子三级跳远运动员水平速度损失原因的运动学分析

通过高速摄影等方法对我国部分男子三级跳远运动员水平速度损失进行了比较分析。结果表明 ,我国运动员在助跑最后阶段有提前准备起跳意识 ,导致后 2步步幅变化过大 ,速度下降 ,进而使单足跳的着板角变小 ,起跳角变大 ,致使第 1跳的向前性差 ,助跑所获取的水平速度不能较好地保持到最后 1跳 ,这是造成水平速度损失的主要原因     

中外男子撑竿跳高优秀运动员最后两步助跑至起跳技术相关运动学参数的比较研究

最后2步助跑至起跳技术是撑竿跳高中的关键技术环节.本文采用文献资料法、比较研究法,数理统计等方法对中外优秀男子撑竿跳高运动员最后2步助跑至起跳技术相关运动学参数进行对照.结果表明,我国优秀男子撑竿跳高运动员在身体重心运动轨迹变化、摆动膝角等多项指标中与世界优秀选手均存在一定差距,揭示我国优秀男子撑竿跳高运动员最后两步助跑至起跳技术的一般性规律与特征.为我国优秀男子撑竿跳高运动员的科学训练提供定量化参考依据.     

我国优秀女子三级跳远运动员助跑最后 两步与起跳速度特征的研究

助跑与起跳重心水平速度对三级跳远成绩具有决定性作用;与世界优秀运动员相比,我国运动员在助跑最后两步离地瞬间重心水平速度和垂直速度呈递减趋势,重心水平速度较小,但在单足跳离地瞬间垂直速度较高,导致了过大的腾起角。     

大学生体育意识、信念及体育行动的调查分析

对跳远运动员来说,助跑速度是决定跳远成绩的重要因素之一.本文采用非接触法,以男女运动员各三名为对象,运用高速摄影机,对受试者最后4步的助跑及起跳动作,对人体重心的水平速度、垂直速度、步频、步长和腾起角进行了研究.     

跳远运动员助跑最后4步运动学技术参数的对比分析

对跳远运动员来说,助跑速度是决定跳远成绩的重要因素之一.本文采用非接触法,以男女运动员各三名为对象,运用高速摄影机,对受试者最后4步的助跑及起跳动作,对人体重心的水平速度、垂直速度、步频、步长和腾起角进行了研究.     

第11届世界青年田径锦标赛男子跳高运动员起跳技术的运动学分析

对第11届世界青年田径锦标赛男子跳高运动员进行起跳技术的三维运动学分析,结果表明:研究对象最后一步技术与世界优秀运动员的差异性小;H2、成绩和重心最大高度均相对较低;起跳点距离横杆垂直面过近;助跑速度和起跳结束时的身体重心垂直速度低;利用水平速度的能力不够;起跳结束时重心垂直速度与垂直加速距离、摆动腿摆动速度与摆动腿水平角、缓冲时间占总时间的百分比与垂直速度呈显著性正相关.     

Carbohydrate ingestion improves endurance performance during a 1h simulated cycling time trial

This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue.     

Science and medicine of rowing: A review

The biology and medicine of rowing are briefly reviewed. Effort in a 2000 -m race is about 70% aerobic. Because the boat (and in some instances a cox) must be propelled, successful competitors are very tall, with a large lean mass and aerobic power. Large hearts may lead to erroneous diagnoses of a cardiomyopathy. Large respiratory minute volumes must be developed by chest muscles that are also involved in rowing. The vital capacity is typically large, and breathing becomes entrained. Expiration cannot be slowed relative to inspiration (as normally occurs at high rates of ventilation) and the limiting flow velocity may be reached, with the potential for airway collapse. Performance is strongly related to the power output at the ‘anaerobic threshold’, and lactate measures provide a guide to an appropriate intensity of endurance training. Peak blood lactate levels are higher in males (commonly 11–19 mmol·l -1 and occasionally as high as 25 mmol·l -1) than in females (9–11 mmol·l -1), probably because males have a greater muscle mass in relation to blood volume. The skeletal muscles are predominantly slow twitch in type, developing an unusual force and power at low contraction velocities. Many rowers have a suboptimal diet, eating excessive amounts of fat. Lightweight rowers also have problems of weight cycling. Aerobic power and muscle endurance often change by 10% over the season, but such fluctuations can be largely avoided by a well-designed winter training programme. Injuries include back and knee problems, tenosynovitis of the wrist and, since the introduction of large blades, fractures of the costae.     

全国城乡学生体质20年动态分析

基于1985、1995和2005年全国学生体质调研数据,对各时期我国城乡学生形态、机能、体能发展水平进行系统地定量研究,动态分析20年全国城乡学生体质发展的特点与规律。主要研究结果：（1）近20年城乡学生生长发育持续提前,城市学生各项形态指标生长水平高于乡村,身高城乡差距缩小,体重、胸围城乡差距加大;（2）城市学生肺活量水平高于乡村,城乡学生肺活量20年持续下降,前10年乡村学生下降快、后10年城市学生下降快;（3）乡村学生800m、1000m跑水平高于城市,城市女生50m跑、仰卧起坐水平高于乡村,其他素质城乡学生水平波动较大;（4）城市女生50m跑20年持续下降,城乡学生800m和1000m跑、城市学生50m×8往返跑20年加速下降,其他素质20年间有增有降发展极不平稳。     

定向运动对大学生身心健康发展的实践研究

采用测量、问卷调查、数理统计等方法,分析定向运动学习前后对大学生身心健康的影响.结果经T检验和x2检验且表明：定向运动不仅能增强学生体质健康水平,而且有助于学生的情绪调节,增强自信心与创新意识,培养勇敢顽强的意志品质,建立良好的人际关系,能有效地促进学生身心健康发展.为了全面提高大学生整体素质,积极实践,构建定向运动课内外一体化教学模式,进行定向运动课程模块化教学,以满足学生的多元化需求.     

Identifying home advantage in international tennis and golf tournaments

A regression analysis of competitors' tournament results in relation to their world rankings was proposed to identify the effect of home advantage in international ‘grand-slam’ tennis and ‘major’ golf tournaments. The results provided little evidence of home advantage in either the grand-slam tennis or the golf tournaments held in 1993. The only possible evidence of home advantage was found in the Wimbledon tennis and the US Open golf championships. Even these findings can be explained, at least partially, by (1) the availability of information concerning the low world rankings of the British tennis players competing at Wimbledon, and (2) selective entry, allowing only the world's top-ranked foreign golfers into the US open golf tournament. In both cases, the lower ranking home competitors have a greater opportunity to perform above their anticipated world rankings. Therefore, provided entry into tennis and golf tournaments is truly ‘open’ to both the host nation's representatives and foreign competitors alike, home advantage does not appear to be a major factor influencing the competitors' performance in such competitions. These findings may be explained by the relatively objective nature of the scoring systems used in tennis and golf, unlike the subjective influence of refereeing decisions on the results of team-games such as soccer.     

摔跤常见技术动作开始的发力特征研究

采用专门研制的摔跤测力装置,对过胸摔、挟颈背、拉臂转移和滚桥技术动作开始发力的力学特征进行测试分析,结果表明,上述动作开始的发力具有力值大和力的梯度大的特点,均有爆发用力的特征。其中过胸摔和滚桥主要把位发力最大,其总合力和力的梯度也最大。     

按摩器刺激对提高普通高校健美操专选学生柔韧性训练效果的实验研究

柔韧素质是健美操专业学生的专项素质之一,通过对普通高校健美操专业学生分组对照进行柔韧性训练的实验研究,认为对训练肌群辅以按摩器振颤刺激,可大大提高柔韧性训练效果。     

我国城市体育自然环境建设与发展的研究

采用实地调查研究、理性思维研究和文献资料调研等方法对主要问题进行了专门研究，提出了进行城市体育场所区域生态功能区划、设计体育生态功能区布局的方案、做好体育场所绿色环境系统规划、制定体育场所生态与绿地管理措施等基本观点，提出了若干城市体育自然环境建设与发展的对策。     

我国体育市场管理法规研究

采用调查法和比较法对全国体育市场立法和管理现状进行调查,对部分较早出台并有一定代表性的省市的体育市场管理法规的立法和管理情况进行了研究,提出了体育市场管理立法和管理的原则、基本程序、措施及其一般模式,为规范全国体育市场管理提供参考依据。     

重新认识体育的社会关联

体育与政治之间存在一个悖论，体育的发展与经济实力之间没有直线相关，体育与教育部分重叠，体育与宗教最为近缘，体育可借用科学手段，体育的艺术禀性日益明显，体育与养生反映着两种人生观。