常识普及：四种泳姿知多少

Breaststroke蛙泳Breaststrokeistheslowestofthefourofficialstylesincompetitiveswimming,butitiscommonlyagreedthatitisbyfarthemostdifficulttodocorrectly.ThehistoryofbreaststrokegoesbacktotheStoneAge.Thelegactionofthebreaststrokemayhaveoriginatedbyimitatingtheswimmingactionoffrogs.蛙泳是竞技游泳的四种标准泳姿中最慢的一种，但它却是公认最难做得标准的一种。蛙泳的起源可以追溯到石器时代。蛙泳中腿部蹬水的动作很可能是模仿青蛙的泳姿而来。Freestyle自由泳FreestyleisanunregulatedswimmingstyleusedinswimmingcompetitionsaccordingtotherulesofFINA.Competitorsinfreestyleswimmingcanuseanyoftheunregulatedstrokessuchasfrontcrawl,dogpaddle,orsidestroke,etc.Mostcompetitiveswimmerschoosethefrontcrawlduringfreestylecompetitions,asthisstyleprovidesthegreatestspeed.Assuchthetermfreestyleisoftenusedasasynonymforthefrontcrawl.根据国际泳联的规定，“自由泳”其实是各种非标准泳姿的统称，包括爬泳、狗刨、侧泳等等。但是在自由泳比赛中多数选手会选择爬泳，因为这种泳姿速度相对较快。因此人们常说的“自由泳”基本就成了“爬泳”的同义词。Backstroke仰泳Thebackstrokehastheadvantageofeasybreathing,butthedisadvantageofswimmersnotbeingabletoseewheretheyaregoing.Itisalsotheonlycompetitionswimmingstylethatstartsinthewater.Backstrokeisanancientstyleofswimming.ThefirstOlympicbackstrokecompetitionwasthe1900ParisOlympicsmen's200metre.仰泳的优势在于便于呼吸，缺点则是游泳者不能看到前方的情况。仰泳也是几种竞技泳姿中唯一一种从水中出发的（其他几种泳姿是从跳台上出发）。仰泳是一种古老的泳姿。奥运史上第一次仰泳比赛是1900年的巴黎奥运会男子200米仰泳。Butterflystroke蝶泳Whileotherstyleslikethebreaststroke,frontcrawl,orbackstrokecanbeswumeasilyevenbybeginners,thebutterflyisamoredifficultstrokethatrequiresgoodtechniquetobefeasible.Itisthenewestswimmingstyleswumincompetition,firstswumin1933.Interestingly,thebutterflykickwasdevelopedseparately,andisalsoknownasthedolphinkick.初学者也许能很容易地掌握蛙泳、自由泳或仰泳，但蝶泳却难得多，对游泳者的技术要求很高。蝶泳出现于1933年，是竞技游泳的几种泳姿中最新的一种。有趣的是，蝶泳的踢水动作是单独发展出来的，而且被叫做“海豚踢”。室外健身器材