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在田径运动中，推铅球是单手投掷的非周期性运动项目。推铅球时的技术方法与场地器械有其独特的特点，因而形成了独特的技术结构。推铅球同掷铁饼一样，都是在圆圈中投掷，左腿都有一个制动，支撑用力的动作，但是左腿用力是一个复杂的过程，而不仅仅是一个简单的动作形式，推铅球时，左腿在最后用力过程中，能否形成合球的支撑技术，对最后用力的效果影响极大。因此，本文就推铅球时如何优化运动技术结构，使之达到比较完善的效果，作一个初步探讨。 相似文献
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铅球最后用力的理论与训练 总被引：5，自引：1，他引：5
在对铅球最后用力概念界定的基础上，重新划分铅球最后用力阶段，并论述了单支撑最后用力的积极意义及专项力量的训练。通过对大量文献资料进行数理统计和综合分析，提出了划分铅球最后用力阶段的新观点：推铅球最后用力阶段，是从滑步过程中支撑腿水平方向上运动结束之时开始到铅球离手的过程。整个最后用力阶段分为单支撑用力和双支撑用力出手两个阶段，单支撑最后用力阶段对减小铅球预先速度的损耗、加快左脚着地和拉长工作肌有重要意义。在训练中采用切割组合训练方法可有效地把力量与技术紧密的结合在一起，加强快速力量训练，尤其下肢爆发力和制动力量。 相似文献
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背向推铅球的滑步技术复杂,是中学体育教学的难点,因学生单手持一定重量的铅球单腿支撑滑动,往往造成身体的起伏而出现停顿或减速,影响最后用力的效果。针对上述问题,我们设计了推铅球“双腿滑步”技术,其技术优点有:1)动作结构自然简单,易掌握,见效快,符合中学教学的实际与特点。2)双腿支撑依次滑动速度快、重心低而稳,易形成最后用力前的预备姿势,便于急骤发力。现将“双腿滑步”动作要领介绍如下:因其它几部分动作要领同现代推铅球要领相同,不作重复介绍。 相似文献
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本文阐述了推铅球过程中左腿支撑用力对提高铅球运动成绩的作用，介绍了正确发挥左腿支撑用力技术作用时应注意的问题及训练方法， 相似文献
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在推铅球最后用力教学中,最常见的错误就是左腿支撑不好（以右手推球为例,以下同）,以及左肩过早地后撤,导致力量分解,影响用力效果和运动成绩。左腿支撑用力是所有投掷项目最后用力的共同点,如果只注意右腿的用力而忽视左腿的撑蹬,则会造成上体前倾而导致铅球出手... 相似文献
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滑步推铅球最后用力技术特征与专项力量训练 总被引：1，自引：0，他引：1
在对铅球最后用力技术特征的基础上,分析了推铅球技术过程中单支撑最后用力的作用。根据推铅球最后用力技术特征,在运动训练实践中采用切割组合训练方法,使专项力量与运动技术训练融于起,加强快速力量训练,尤其下肢爆发力和制动力量。 相似文献
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再论推铅球的最后用力 总被引：9，自引：0，他引：9
在对推铅球最后用力概念界定的基础上 ,重新划分推铅球最后用力的阶段。查阅了国内外有关的文献资料 ,在此基础上进行数理统计分析 ,提出了划分推铅球最后用力阶段的新理论 :推铅球最后用力阶段是从支撑脚着地后积极蹬伸产生向前水平支撑反力开始到铅球离手的过程。整个最后用力阶段分为单支撑和双支撑 ,单支撑最后用力阶段对左趾向前水平位移、身体重心速度水平向前增量有积极的作用 ,促进左脚积极着地进入双支撑最后用力阶段。在训练中选择提高下肢离心 -向心收缩能力的练习 ,提高力量训练效果。 相似文献
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铅球教学技术比较复杂，动作结构要求连贯稳定，各运动环节的协调衔接与组合要形成正确的运动链和力的传递途径，在实际教学中往往只重视了主要技术环节的教学，忽视了推铅球过程中非投掷臂动作技术的配合教学，从而影响整个技术动作的一致性及全身的协调用力，直接影响学生推铅球的成绩。文章试图从生物力学角度对其进行分析，以便完善学生推铅球整体技术动作，从而提高运动成绩。 相似文献
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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. 相似文献
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Roy J. Shephard 《Journal of sports sciences》2013,31(7):603-620
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. 相似文献
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重新认识体育的社会关联 总被引：3，自引：1，他引：2
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。 相似文献
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本文在专家访谈、问卷调查、数理统计和文献资料分析的基础上,探析了上海社区体育竞赛参与者的特点、参与者对社区体育赛事运作管理的看法等问题。在此基础上从引进社区体育赛事的志愿者、整合社区体育赛事的各种资源、开发社区体育竞赛的无形资产、组建非营利性的专业团队、规范社区体育赛事的服务管理等方面提出了进一步满足上海社区居民日益增长的体育竞赛参赛需求的对策与措施。 相似文献
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对全面把握游泳训练环节的探讨 总被引：4，自引：0，他引：4
从系统观点出发,结合训练实践,对全面把握游泳训练环节进行探讨。认为应强化非智力因素在运动员多年训练中的作用,在育材全过程中不断选材,从整体上把握动态训练的全过程,把培养高水平运动员的整个过程置于一个严格的科学控制之下。 相似文献
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影响和限制耐力性运动项目的成绩的生理因素是复杂的和多方面的,取决于训练的强度和运动成绩.大强度持续性运动可导致呼吸肌疲劳.运动性呼吸疲劳可能在决定运动耐量方面起到关键的作用：一方面通过直接影响运动肌力量的生成（外周疲劳）,另一方面,通过肢体用力自感不安反馈引起工作肌运动单位输出功率下降（中枢疲劳）.对呼吸肌进行训练,可能有助于提高耐力性项目的运动成绩. 相似文献
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青少年业余足球运动员运动倾向性5因素结构模型初探 总被引：3，自引：0，他引：3
根据Scanlan等人最新提出的运动倾向性理论模型,结合我国实际情况建立了青少年足球运动员运动倾向性5因素结构模型。运动倾向性被定义为:渴望和决心继续参加足球运动的心理状态。所建立的5因素结构模型认为,运动倾向性是由运动乐趣、参与选择、个人投入、社会约束及参与机会5个因素决定。经确定5个决定因素和运动倾向性的操作定义,编制了相应调查问卷,通过对北京市252名青少年足球运动员实测结果,建立运动倾向性及其影响因素的协方差结构模型,用Lisre 18分析的结果表明:该运动倾向性模型比较符合北京青少年足球运动员。其中运动乐趣、个人投入、参与机会和参与选择4因素对运动倾向性有影响;社会约束对运动倾向性影响不大。 相似文献
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The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s :age 23 +/- 4 years;body mass 69.7 +/- 9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23 +/- 4 years; body mass 72.7 +/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO 2max , running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol.l -1 ; and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO 2max , running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol.l -1 or the lactate minimum speed.In the training group, there was a significant increase in VO 2max (from 47.9 +/- 8.4 to 52.2 +/- 2.7 ml.kg -1 .min -1 ), running speed at the maximal lactate steady state (from 13.3 +/- 1.7 to 13.9 +/- 1.6 km.h -1 ), running speed at the lactate threshold (from 11.2 +/- 1.8 to 11.9 +/- 1.8 km.h -1 ) and running speed at a blood lactate concentration of 3 mmol.l -1 (from 12.5 +/- 2.2 to 13.2 +/- 2.1 km.h -1 ) (all P ? 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0 +/- 0.7 to 10.9 +/- 1.7 km.h -1 ). The results demonstrate that the lactate minimum speed,when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity. 相似文献