游泳时自由泳动作的"锚定手"解析

前伸手掌相当于一个锚，身体是一只船（另一手就是撑船）
自由泳的锚定手
  

六个游泳诀窍
   （这六个诀窍)做的越好就会游的越快，而不用练的更多。
    假定有一池的健壮的泳客或在做交叉训练的运动健将，你问他们为什么会在这，会得到所有平常的——有说服力的——理由：游泳锻炼不会受伤；在做全年提高潜能的训练；为了身体更健康；有些人则是刚开始涉足三项全能。只是到后来某些运气好的人才会无意中说出最好的理由。那就是谁都可以游得更快，用不着身体要象牦牛那样好：）
    很多人刚开始游泳时会本能的认为游泳是和跑步骑车一样的健身运动。想游得更快么？多游就行了。但是，游泳其实更像是网球、高尔夫或滑冰。更好的成绩来自于训练的方法，而不是训练的量。
    这是因为决定游得快慢的最重要因素不是大块的肌肉或是惊人的VO2 MAX(注)数值，而是更长的划水。每次划水时你移动的距离越长，你就游得越快。在对1988年汉城奥运会的所有游泳比赛的计算机辅助研究中，最后得出的结论就是在每场比赛中，游得最快的人都是用最少的划水次数游完的。增加划水长度就会游得更快...而且会更省力。
    "好"，你说,"可是我怎么才能做到这一点呢?"有下面两条途径。
    第一条是减小前进时水对你的阻力。你可以通过改善身体的平衡、体位和体形做到这一点。调整一下姿势，就算没有别的改进，不是很完美的划水也能让你游得更远更快。
    第二条是确定发力点和更有效地使用手。大多数人（和教练）倾向于一开始就把重点放在本条，但这样做提高速度的可能性只有30％。所以要把首要重点放在减小阻力上，那样的话提高速度的可能性会更大。  
    改变一下你原有的游法。
    三个减小阻力的窍门：  
    1，使身体变长。根据船结构的定律（1871年由R.E.Froude，英国船舶设计者）：长船要比短船快。从那时起，“Froude 数值”被用来估测帆船的速度潜力。对人体来说也一样。在整个游泳过程中，身体伸得越长，在划水的短暂停顿期间速度就会保持得越好。一些简单的应用：自由泳时，手入水之后再前伸一点，向后划水之前多停留一会。这样在另一只手划水及移到前面时身体会变得更长。蛙泳时，双臂划水后，向前伸展成流线型并保持到蹬腿动作完成。身体越长，速度越快。
    2，改善“船壳”设计。虽然无法选择天生的体形，但是在某种程度上可以设计身体行驶在水里时的形状。改善姿势和体形（圆滑度）。在练习力量或练习推进技巧以便游得更快之前，先试一试更简单的方法：确认已经尽一切可能来减小粘滞力或阻力。把身体上所有的边都变得圆滑，减小身体和水面的夹角；想象在一根很细的管子里游，而不是一个粗的下水管。使划水和移臂在横截面上更紧凑（不是更短）来适应狭窄的空间。
消除头部的摇摆晃动和臀部腿部的鱼尾状摆动。更重要的是...  
    3，用身体侧面来切水。注意过相比起人来，鱼是怎样用身体切水的吗?当在自由泳和仰泳中采取更像鱼那样的侧卧位时，水会流过身体的两个表面，胸和背，同胸部朝下水几乎都是从身体下流过相比，水的粘滞距离只有一半。阻力也差不多减少一半。自由泳时不要胸部向下（平卧），仰泳时不要背部向下（平卧），身体从一边转动到另一边时要尽快转过这些位置。   
停止浪费能量。
    现在你已经消除了身体与水的搏斗，有三个窍门可以用来更好的获得推进力。
    4，正确的发力。在自由泳和仰泳中，转动髋部除了减小阻力外还有其它的好处——帮助使用躯干的力量来提供动力。注意过棒球投球手投球，网球手发球，高尔夫球手击球吗？没有人是用手臂发力的，都是侧身对着发球的方向，先是髋部开始发力，接下来是肩膀。最后才是手臂，象鞭子一样抽打。游泳也是如此。自由泳和仰泳中，力量来自髋部有力的转动，然后通过躯干肌肉传到手臂。手只是髋部力量作用于水的点。划水的节奏和频率来自髋部，而不是手臂。   
    5，锚定手。划水时不要拉手向后。而是尽可能近的将手锚定在一个固定的位置，用胸部和背部的肌肉来将身体拉过锚定手的点。有两个好方法可以提高这个能力：   
    . 先攥紧拳头游，再松开手感觉如何更好的抓水。
    . 把手向后拉水的速度与身体的前进速度匹配起来。 拉水时避免“轮子打滑”。想象在水中抓住了一根横杠，把身体拉过去。当感觉有进步时，再握上拳头练习。
    6，在提高速度时要保持住划水长度。想游得更快时，先尽量增大单次划水的长度。接着增大髋部转动的力量。最后才是加快划水的频率，加快频率时，不要象大多数游泳者那样缩小划水长度。如果正常用18次划水游完一个池长，但在游快时却要用20下，尽管速度增加了一点，却牺牲了划水的效率。尽量用18次划水来游得更快。
    最后，不要把上面所说的任一种练习当成是额外的训练。它只是更好的利用了你一直都在做的训练。  
    注：VO2 MAX即最大吸氧量，是指人体在进行有大量肌群参加的力竭性运动中，当氧运输系统中的心泵功能和肌肉的用氧能力达到本人的极限水平时，人体每单位时间所能摄取的氧量。最大吸氧量的大小对耐力素质的影响十分明显。因为最大吸氧量本身就是反映有氧耐力水平的一个重要指标。最大吸氧量越大，有氧耐力水平也就越高。在有氧过程为主的运动项目中，运动员的最大吸氧量明显大于其他人。同样，最大吸氧量水平越高，耐力性运动的成绩就越好。

Six Swim Tips
Do these better and swim faster...without training more!

Take a pool of fitness swimmers or cross-training Masters athletes and ask them why they're there. You'll get all the usual--and compelling-- reasons: injury-free workouts, year-round exercise potential, better overall fitness, for some dipping a toe into the triathlon. It's only later that the luckier ones stumble onto the best reason of all. Namely you can get much faster without necessarily having to become a great physical specimen.  

Many people come into swimming intuitively thinking it's just another fitness activity like running and biking. Want to get faster? Do more miles of training. But swimming is more like tennis, golf, or skiing. Better performance comes from how not how much.

That's because the single most important factor in fast swimming isn't big muscles or an impressive VO2max; it's a long stroke. The farther your body travels with each stroke, the faster you'll swim. A computer-aided study of all swimming events at the 1988 Seoul Olympics showed conclusively that in every event the fastest swimmers took the fewest strokes per pool length. Make your own strokes longer and you'll also swim faster...and easier.

"Okay," you say, "Now how do I do that?" There are actually two ways.

The first is eliminating resistance caused by the water to your forward momentum. You do this by improving body balance, position, and alignment. Clean up your body position, and even if you don't make any changes in your stroke, your still imperfect stroke will move you further and faster.

The second way is creating more propulsion by locating your power source and using your hands more effectively. Most people (and coaches) tend to focus on this first, but it provides only about 30% of your opportunity to become faster. So get to work on the eliminating skills first because they offer more opportunity for improvement.

Get Out Of Your Own Way

The three eliminating skills are:

1. Make your body longer. It's a fact of naval architecture (discovered in 1871, by R.E. Froude, an English ship designer). Longer boats go faster. Ever since, "Froude numbers" have been used to estimate the potential speed of sailboats. The same goes for your body. The longer your body during all phases of all strokes, (ital.) the better it will hold its speed during the slight pauses between strokes. Some simple applications: In freestyle, extend your hand a little farther after it enters the water and leave it there just a moment longer before pulling back. That keeps your body longer while your other hand completes its stroke and takes over the front position. In breaststroke, after pulling, stretch and streamline both arms forward and keep them there until after you complete your kick. Longer body, faster body.

2. Improve your hull design. Though you didn't get to choose the body you were born with, to a certain extent, you can design the hull or vessel you ride the water with. Improve your body position and alignment (sleekness). Before working on your power or propulsion technique to swim faster, take the easier way: Make sure you've done everything possible to eliminate drag or resistance. "Round off" all edges; eliminate sharp angles in the confrontation between your body and the water. Imagine yourself swimming down a very narrow tube, as opposed to say a large sewer pipe. Make your stroke and recovery more compact (but not shorter!) more compact in cross-section to fit the narrower space. Eliminate head wagging and hip/leg fishtailing. And most importantly...

3. Cut the water on your side. Ever notice how fish cut the water compared with humans? When you get into the more fishlike sidelying position in freestyle and backstroke, the water passes across two surfaces of the body, chest and back, has to travel only half as far to get out of your way when you're chest down with almost all of it flowing under you. That reduces drag by as much as half. Instead of lying on your stomach in freestyle or your back in backstroke, pass quickly through those positions while rolling from one side to the other.

Stop Squandering Energy

Now that you've eliminated ways your body fights the water, there are three ways you can create forward momentum better.

4. Use the real power source. Rolling your hips in freestyle and backstroke is good for something beside drag reduction--it also helps you tap the power in your torso or core muscles. Ever notice how a baseball pitcher throws, a tennis player serves, a golfer drives? None gets his power from the arms. All standing sideways to the direction in which they want to launch the ball, then start the movement by bringing the hips through first, followed by the shoulders. The arm comes last, basically cracking the whip. Same thing in swimming. In freestyle and backstroke, power originates with a brisk hip roll on each stroke, then is transferred through your torso muscles to the arm. Your hands are simply the point where hip rotation power is applied to the water. Stroke rhythm or tempo is also set in the hips, not the arms.

5. Anchor your hands. Don't stroke by pulling your hands back through the water. Instead, anchor them in as near a stationary position as possible and use chest and back muscles to pull the body past the point where you anchor your hands. Two good ways to improve this ability:

Swim with fists clenched then open them to feel how to hold water better.
Match the speed of your hands pulling back to the speed of your body moving forward. Avoid "spinning your wheels" in the pull. Imagine grabbing a rung in the water and pulling your body past it. When you begin to feel yourself doing this better, try to do it with your fists closed.
6. Keep your stroke length as you build speed. When trying to swim faster, first maximize distance per stroke. Next addpower through hip rotation. Only at the end, do you speed up your stroke tempo, and when you do, don't lost distance per stroke, as many swimmers do. If you can cover a length of the pool in 18 strokes, but find you take 20 strokes when you try to swim faster, then you've sacrificed efficiency, even if you have gained a little speed. So try to swim faster at 18 strokes instead.

Finally, don't think of any of these exercises as extra training. It's making better use of the training you already do.