B1 中級 1579

 So today we are going to go back to fundamentals. All right? We're going to-- we're going to pay attention to, and we're going to learn from, the three basic laws that govern every stroke you take. No matter whether it's fly-back, breast or free. The first group of laws are probably the most important ones. And those are the ones that I call the number one enemy of the swimmer. Those are the laws of drag. The forces of drag. They're the ones that slow you down. We have to really pay attention to how to minimize those. The second group of laws are the ones that allow you to go. The laws of motion or propulsion. And we have to maximize power to the best of our ability to get down to the other end of the pool. And the third law, which is called the law of inertia, basically says, that a body in motion wants to stay in motion. That means that we want to keep our speed constant. There's really only two strokes that we can do that in, and that's free and back. The fly and breast are stop and go strokes. They don't obey that law. But in free and in back, we can. We can come close to doing that. So we're going to work on some drills for each of those categories. (narrator) Sculling with the head above water while doing flutter kick is a good way to demonstrate that an elevated head also changes the body's position in the water. Olympic champion and world record holder Roland Schoeman sculls with his hands extended forward, moving them outward and inward in a continuous motion. While his head is above water, and his feet near the surface, his back is arched and his bum is several inches below the water level creating a curve to his body. For any swimmer, tall or short, deviating from a straight body position will create a lot more frontal drag particularly when swimming fast. Elevating the head in freestyle also contributes to increasing frontal drag by creating more of a bow wave striking against the swimmer's head moving forward. Ultra marathon swimmer Lexie Kelly demonstrates how this overly elevated head causes a huge bow wave colliding against her head, slowing her down with every stroke she takes. From underwater, the elevated head position prevents her body from being straighter and more streamlined. So this time, I want you to drop your chin down almost to your chest. And I want you to scull with your head down in that position, and now notice where your bum is in the water in the body position. (narrator) Once the head is in the down position with the line of sight directed toward the bottom of the pool rather than forward, the body position changes instantly. The bum comes up to the surface, and from head to toes the body stays in alignment. With his elbows held high in front, arms nearly straight, Roland keeps constant pressure on his hands with the direct sweep outward, then immediately reverses the direction of the hands inward. With this drill, the sculling hands are helping to lift the front of the body. But all the propulsion comes from the legs. If you're a beginner or don't have enough propulsion from your kick to do this drill well, try doing it with fins and snorkel on to make it easier. Don't do a little breast stroke pull, which causes the body to bounce up and down, or allow the hands and elbows to drop too deeply in the water, or allow the elbows to fall back to the ears, all of which will produce more frontal drag. When the head is positioned correctly in freestyle as shown by Japanese champion Junya Koga the bow wave flows nicely over the top of the head. The body remains a line on the surface. And he moves forward with the least amount of resistance possible. [WATER BUBBLING NOISES]
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# Swimisodes - Improve Freestyle Technique - Head Position

1579
Harrison Mia 2016 年 2 月 27 日 に公開

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