游泳动态阻力研究的现状评述

本文介绍了几种游泳动态阻力的测试方法--MAD测试系统、速度扰动法、生物能量转换法、模型法和牵引法等。通过动态阻力的测试方法和研究成果的回顾和评价,指出游泳时人体动态阻力的测试还存在由于研究者理解和认识的不同所带来测试手段、研究方法以及研究结果存在较大差异的现状。同时,由于游泳动态阻力的测试在方法学上尚有诸多难点,因此在这些研究中所作的假设和对数据处理的方法使所得结果缺乏实际应用价值。本文指出,进一步深入开展游泳动态阻力的研究,提出科学、合理、简便、实用的测试和研究方法,并用于指导游泳训练实践,是今后游泳科学研究与训练中的重大课题之一。     

对游泳中阻力与推进力问题的研究综述

游泳运动员在游进中受到的阻力有3种：摩擦阻力、形状阻力和波浪阻力。形成阻力的因素主要有形状、截面、速度、水的密度。根据身体运动的方式存在2种阻力：主动阻力和被动阻力。研究认为：1)游泳时的推进力有阻力推．进力和升力推进力之分；2)在最大速度情况下，四种泳式的主动阻力不同；3)采用流体阻力系数Cx(ad)来区别动作效果只适用于在较高的速度区域；4)比较男子和女子4种泳式在所有速度区域的总机械功率(Pto)，没有发现显著性差异；5)游泳时追求最大功率对于游泳运动员的意义是不大的，重要的是提高流体动力学的效率。     

游泳运动员利用脚蹼和呼吸管训练可以提高成绩

脚蹼和呼吸管是游泳训练的主要器具，脚蹼有双蹼和单蹼之分。研究表明，无论是双蹼单蹼、还是呼吸管都可有助于游泳运动员提高成绩。通过在游泳训练中运用脚蹼和呼吸管，运动员在以下几个方面可得到改进：1．能找到最佳身体位置，尽可能减少阻力；2．改进打腿技术；3．改进呼吸     

游泳技术基本原理及要点

技术训练的目的是通过不同的技术练习手段，使运动员掌握合理的游泳技术。因此游泳技术训练就要符合游泳技术的力学、解剖学原理。 一、外形姿态与游泳技术 游泳中，运动员受到的阻力大小与物体的形状有很大的关系。在水里，运动时在物体前后形成的压力差引起的阻力，称为压差阻力，也被称为形状阻力。不同形状的物体在水中运动时所受到的形状阻力是不同的。     

游泳水槽在现代游泳训练和科研中的应用

综述了游泳水槽在各个国家的发展和研究概况，其中，游泳生理学的研究主要包括了运动员的有氧、无氧能力和技术经济性的研究；在生物力学方面，主要的研究集中在运动学和动力学两个方面；概括了游泳水槽在游泳速度训练和水上专项力量训练方面的应用。在水槽将来的应用和发展中，游泳运动技术与体能研究相结合仍将是研究的重点，同时，通过生理学的测量对游泳过程有了更加深入的了解后，可以对训练的有效性进行更深入的研究。     

流体力学基本原理在蛙泳腿技术中的应用

游泳是以水为介质的运动项目，人在水中游进会受到水的阻力，同时通过肢体与水的“作用力与反作用力”获得游进的推进力，游泳的阻力和推进力的大小会影响游泳速度。本文运用“流体力学的基本原理”对蛙泳腿部技术进行力学分析，阐述如何减小蛙泳腿的阻力，增大蛙泳腿的推进力，从而提高蛙泳游速。     

广东省优秀游泳运动员肩屈伸肌等速力量指标特征

人在水中运动受到水的阻力比在陆上所受阻力大许多,因此游泳运动员的力量素质和耐力素质是十分重要的.无论哪种泳式都要求臂、腿、头、躯干协调配合,其中臂的划水是产生动力的主要源泉.以往由于研究仪器的限制,对动态力量的测试十分复杂也不准确.作者借助等速测力系统CYBEX 300对广东省游泳队男女运动员共18名进行了动态肩屈、伸肌力各项指标的研究,这是在国内首次对游泳运动员肩关节屈伸肌进行等速力量测试.     

简论现代游泳训练的发展

现代游泳训练已发展了100余年。100余年来，游泳训练从无到有，从简单的技术改进，到多种训练方法和手段的运用；从单纯的追求训练数量到注重强度与量的结合；从注重发展运动员的体能到强调技术和专项能力并重发展。简单地说，游泳训练的发展同人们对游泳项目本质的认识紧密联系。随着对游泳运动本质更深入的研究和认识，游泳训练的发展进入了一个新阶段。对于我国游泳工作者来说，最重要的一点是应具备更深刻的科学观念，对游泳运动训练的认识应建立在科学思维基础上。因此，研究和分析世界游泳训练发展趋势，对于更好地把握训练方向有重要意义。     

无板打腿在少儿自由泳技术训练中的运用

1 前言：近几年我国游泳事业发展较快，不少新苗涌现出来，给游泳事业带来了生机和活力，加之我国全民健身法的实施、使少儿参加游泳锻炼人数日益增多。在普及游泳训练中，多数少儿游自由泳时身体控制不住，身体下沉，腰部扭动、摆动过大。针对这些较普遍的技术问题，我们在教学训练中用无板打腿对这些技术问题进行改进，从而减少了水中阻力，提高了自由泳成绩，具有较好实效。     

CFD仿真技术在游泳运动力学问题研究中的应用

针对游泳运动中关键的推进力和行进阻力力学问题,采用传统的试验研究方法具有成本高、可重复性低、无法解释本质机理等局限性。CFD仿真技术作为一种高效的流体问题研究手段,已经被国内外学者广泛应用于处理此类问题中。通过综合分析、归纳近20年来国内外关于CFD在游泳运动中应用的文献报道,从CFD仿真技术的特点及基本步骤出发,总结了实施该技术处理推进力和行进阻力问题的手段与成果,并探讨了相关的发展趋势,为我国游泳科研学者运用CFD仿真技术提供借鉴。     

Effect of a Fast-skin 'body' suit on drag during front crawl swimming

The effect on drag of a Speedo Fast-skin suit compared to a conventional suit was studied in 13 subjects (6 males, 7 females) swimming at different velocities between 1.0 and 2.0 m.s-1. The active drag force was directly measured during front crawl swimming using a system of underwater push-off pads instrumented with a force transducer (MAD system). For a range of swimming speeds (1.1, 1.3, 1.5 and 1.7 m.s-1), drag values were estimated. On a group level, a statistically non-significant drag reduction effect of 2% was observed for the Fast-skin suit (p = 0.31). Therefore, the 7.5% reduction in drag claimed by the swimwear manufacturer was not corroborated.     

Contribution of uncertainty in estimation of active drag using assisted towing method in front crawl swimming

Active drag force in swimming can be calculated from a function of five different variables: swim velocity, tow velocity, belt force, power output and exponent of velocity. The accuracy of the drag force value is dependent on the accuracy of each variable, and on the contribution of each variable to drag estimation. To calculate uncertainty in drag value, first the derivatives of the active drag equation with respect to each variable were obtained. Second, these were multiplied by the uncertainty of that variable. Twelve national age and open level swimmers were recruited to complete four free swimming and five active drag trials. The uncertainties for the free and the tow swim velocities, and for the belt force, contributed approximately 5–6% and 2–3% error, respectively, in calculation of drag. The result of the uncertainty of the velocity exponent (1.8–2.6) indicated a contribution of about 6% error in active drag. The contribution of unequal power output showed that if a power changed 7.5% between conditions, it would lead to about 30% error in calculated drag. Consequently, if a swimmer did not maintain constant power output between conditions, there would be substantial errors in the calculation of active drag.     

Swimming

Abstract

The effect on drag of a Speedo Fast‐skin suit compared to a conventional suit was studied in 13 subjects (6 males, 7 females) swimming at different velocities between 1.0 and 2.0 m?s^‐1. The active drag force was directly measured during front crawl swimming using a system of underwater push‐off pads instrumented with a force transducer (MAD system). For a range of swimming speeds (1.1, 1.3, 1.5 and 1.7 m?s^‐1), drag values were estimated. On a group level, a statistically non‐significant drag reduction effect of 2% was observed for the Fast‐skin suit (p = 0.31). Therefore, the 7.5% reduction in drag claimed by the swimwear manufacturer was not corroborated.     

A new device for estimating active drag in swimming at maximal velocity

A new device was designed to measure the active drag during maximal velocity swimming based on the assumption of equal useful power output in two cases: with and without a small additional drag. A gliding block was used to provide an adjustable drag, which was attached to the swimmer and measured by a force transducer. Six swimmers of national standard (3 males, 3 females) participated in the test. For the males, the mean active drag ranged from 48.57 to 105.88 N in the front crawl and from 54.14 to 76.37 N in the breaststroke. For the females, the mean active drag ranged from 36.31 to 50.27 N in the front crawl and from 36.25 to 77.01 N in the breaststroke. During testing, the swimmer's natural stroke and kick were not disturbed. We conclude that the device provides a useful method for measuring and studying active drag.     

Measurement of active drag during crawl arm stroke swimming

In order to measure active drag during front crawl swimming a system has been designed, built and tested. A tube (23 m long) with grips is fixed under the water surface and the swimmer crawls on this. At one end of the tube, a force transducer is attached to the wall of the swimming pool. It measures the momentary effective propulsive forces of the hands. During the measurements the subjects’ legs are fixed together and supported by a buoy. After filtering and digitizing the electrical force signal, the mean propulsive force over one lane at constant speeds (ranging from about 1 to 2 m s^‐1) was calculated. The regression equation of the force on the speed turned out to be almost quadratic. At a mean speed of 1.55 m s^‐1 the mean force was 66.3 N. The accuracy of this force measured on one subject at different days was 4.1 N. The observed force, which is equal to the mean drag force, fits remarkably well with passive drag force values as well as with values calculated for propulsive forces during actual swimming reported in the literature. The use of the system does not interfere to any large extent with normal front crawl swimming; this conclusion is based on results of observations of film by skilled swim coaches. It was concluded that the system provides a good method of studying active drag and its relation to anthropometric variables and swimming technique.     

Measurement of active drag during crawl arm stroke swimming

In order to measure active drag during front crawl swimming a system has been designed, built and tested. A tube (23 m long) with grips is fixed under the water surface and the swimmer crawls on this. At one end of the tube, a force transducer is attached to the wall of the swimming pool. It measures the momentary effective propulsive forces of the hands. During the measurements the subjects' legs are fixed together and supported by a buoy. After filtering and digitizing the electrical force signal, the mean propulsive force over one lane at constant speeds (ranging from about 1 to 2 m s-1) was calculated. The regression equation of the force on the speed turned out to be almost quadratic. At a mean speed of 1.55 m s-1 the mean force was 66.3 N. The accuracy of this force measured on one subject at different days was 4.1 N. The observed force, which is equal to the mean drag force, fits remarkably well with passive drag force values as well as with values calculated for propulsive forces during actual swimming reported in the literature. The use of the system does not interfere to any large extent with normal front crawl swimming; this conclusion is based on results of observations of film by skilled swim coaches. It was concluded that the system provides a good method of studying active drag and its relation to anthropometric variables and swimming technique.     

Variability in Measurement of Swimming Forces

An analysis was conducted to identify sources of true and error variance in measuring swimming drag force to draw valid conclusions about performance factor effects. Passive drag studies were grouped according to methodological differences: tow line in pool, tow line in flume, and carriage in tow tank. Active drag studies were grouped according to the theoretical basis: added and/or subtracted drag (AAS), added drag with equal power assumption (AAE), and no added drag (ANA). Data from 36 studies were examined using frequency distributions and meta-analytic procedures. It was concluded that two active methods (AAE and ANA) had sources of systematic error and that one active method (AAS) measured an effect that was different from that measured by passive methods. Consistency in drag coefficient (Cd) values across all three passive methods made it possible to determine the effects of performance factors.     

Variability in measurement of swimming forces: a meta-analysis of passive and active drag

An analysis was conducted to identify sources of true and error variance in measuring swimming drag force to draw valid conclusions about performance factor effects. Passive drag studies were grouped according to methodological differences: tow line in pool, tow line in flume, and carriage in tow tank. Active drag studies were grouped according to the theoretical basis: added and/or subtracted drag (AAS), added drag with equal power assumption (AAE), and no added drag (ANA). Data from 36 studies were examined using frequency distributions and meta-analytic procedures. It was concluded that two active methods (AAE and ANA) had sources of systematic error and that one active method (AAS) measured an effect that was different from that measured by passive methods. Consistency in drag coefficient (Cd) values across all three passive methods made it possible to determine the effects of performance factors.