一个手能抓多少网球(网球用几只手打球)
翻译：PMOS1
因为水是液体，它的力学特性与我们陆地上的情况有所不同。学会如何对水施加带有有控制的压力会比使用蛮力的方式要有效得多。力量的大小仍然是一个重要的因素但施压方式却更加重要，特别在所有游泳姿势划臂过程的抓水阶段更是如此。
游泳速度取决于推进中对水施压的方式，同时要最大程度地减小使你变慢的一切阻力。特别在爬泳和蝶泳中，不仅只是用手掌来对水产生压力，整个前臂都要用于施压。这就是为何长袖潜水衣在前臂位置有带纹理的补丁块来帮助游泳者去抓到更多的水，也就是让他们的前臂能够对水施加更多的压力。
施压练习
用下面这些方法来改善你的爬泳和蝶泳的抓水抱水技术，体会如何能够使得对水施加的压力增大。
手入水以后，要关注你的指尖位置。当你开始启动抓水动作时，指尖要向下指向游泳池底。接着要关注你的肘部，特别是你弯曲手臂时候形成的肘尖的指向。把那个肘尖“点”向外转动使得你的前臂可以跟随你的手指尖的转为向下方向。
你会感觉到你的肩膀有点往耳朵方向上耸，觉得背阔肌（飞鼠肌）用上力了，或者有点拉伸了。
用你的手掌和前臂锚定住水，把身体拉过手掌位置，前臂和手掌划拉水要逐渐加速。
正如常言所说的那样：知易行难。游泳练习就是要让你能够保证把动作做得正确，因此周密的不断重复练习是最好的学习手段。下回去游泳池就开始尝试这些练习吧。
握拳游练习
握拳游是一个练习使用前臂来抓抱划水的非常好的方式。
对于爬泳，使用8字浮漂。这样你就不至于依靠强有力的打腿来补偿抓抱水能力的弱点。对于蝶泳，戴上脚蹼。大多数的人会觉得练习很有难度，但也是很有益的。如果你能够使用浮漂完成练习，就挺牛逼的。
别自己欺骗自己！你要做到象是要握拳打人一般地攥紧拳头。其中的道理在于通过握拳把手掌的划水面消失，只靠前臂来抓抱和划水。要是你抵御不住松开拳头的诱惑而老是张开手掌，就每只手抓个网球做练习吧。
划手掌练习
用非传统的方式来使用划手掌也是一个好主意。
把划手掌的系带去除掉，用你的手指抓住划手掌的前沿。
抓握住划手掌靠在手掌和前臂处，如果游过50码的距离你就会觉得手指酸痛，那就表明你低肘了，划手掌离开了前臂位置。
也尝试用这种练习方式来游蝶泳
检查一下练习是否做得正确？
如何知道你是否做到了正确的练习方式？答案是可以根据身体的反馈信息来判断。如果你觉得肱三头肌和背阔肌用上力了，那么很可能你就做到了正确的动作。如果你觉得只是肩膀的前方用力，可能就表明动作不那么正确。这种情况下，请让朋友帮忙拍个视频，或者能够找教练咨询一下更好。
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Swimming is different
Because water is liquid, different rules apply from those we encounter on land. Learning to exert controlled pressure on the water will be more effective than applying brute force. Strength is still an important element but pressure is more important, and this is especially true for the catch phase of all strokes.
Swimming velocity depends upon putting pressure on the water in a propulsive way while minimizing any drag forces that could slow you down. And particularly in freestyle and butterfly, it’s not just the hands that you should be looking to for creating this pressure on the water—it’s also the forearms. This is why long-sleeved wetsuits have textured patches on the forearms to help swimmers catch more water—i.e., put more pressure on the water with their forearms.
Pressure Drills
Use these tips to improve your catch and pull in both freestyle and butterfly and watch how the pressure you exert on the water increases.
After the hand enters the water, think about where your fingers are. They should pitch down toward the bottom of the pool as you initiate the catch.
Think about your elbows, and specifically where the point of your elbow is (that’s the part that makes a point when you curl your arm). Rotate that ‘point’ outward so that the forearm can follow the fingertips into the down position.
You should feel your shoulders shrug up by your ear a bit and feel your latissimus dorsi (flying squirrel muscles) engage, or open a bit.
Anchor the hands and forearms in the water and pull yourself over your hands. Accelerate your hands and arms through the pull.
As the saying goes, understanding it is one thing and doing it is another. Swimming is all about making sure you’re doing the movement correctly so thoughtful repetition is the best way to go. Next time you are at the pool try these drills.
Hands-in-Fists Drill
The hands-in-fists drill is an excellent way to practice the catch and pull with the forearm.
For freestyle, use a pull buoy. That way you won’t compensate for a lack of catch and pull by having a strong kick.
For butterfly, use fins. Most swimmers find it very challenging but also very instructive. If you can do it with a pull buoy, that’s awesome.
Don’t cheat! Make a true fist like you’re going to punch something. The point is to take the surface area away from the hands and make you rely on the forearms. If you simply can’t resist the urge to open your hand, hold a tennis ball in each hand.
Paddle Drill
Using paddles in a non-traditional way is a good idea, too.
Remove the straps from your paddle and wrap your fingers over the front edge.
Hold the paddle to your palm and forearm. If at the end of 50 yards, your fingers are sore, it might be because you’re dropping your elbows and the paddle is pulling away from your forearm.
Try this drill for butterfly as well.
Is This Right?
How do you know if you’re doing it right? The answer can be the feedback you get from your own body. If you feel the effort in the triceps and the lats, then you’re most likely doing it right. If you feel the effort in the front of the shoulder, then you may be a little out of position. Have a friend video you if this is the case, or better yet, ask a coach.
