By Jonathan Cain of SwimLabs
Imagine for a moment that you and I are at the pool, and we have two swimming toys: a Pool Noodle, and a Diving Torpedo. I take the Torpedo, you the Noodle, and we have a contest to see which one moves farther through the water. Would you bet with me that your Noodle would win?
I’m guessing that you probably wouldn’t, and with good reason. All other things being equal, the Torpedo will travel further than the Noodle. This is in part because of a simple equation of physics. Work equals force multiplied by distance. This equation is of key importance, not just for Noodle vs. Torpedo races, but also in how we swim and move in general.
Here’s an easy way to think about it. How far I am able to swim forward during each stroke (Work) is dictated by how strongly I am able to push myself against the water with my arms and legs (Force) multiplied by the length of my underwater stroking movement (Distance).
In the example of the Noodle vs. the Torpedo, the biggest reason that the Torpedo is able to do more work (move farther in the water) is because its stable shape allows for a better “Center of Pressure”. This is a term in hydrodynamics that refers to how force tends to act through a single point or plane on a body. The torpedo’s rigid shape and “tail fins” stabilize its position in the water. This concentrates the force with which it was thrown with along a much smaller area than the noodle, allowing it to hold a stable position in the water over a longer distance. This means that the force acting on the torpedo is dissipated more slowly than the noodle’s, allowing it to move further.
So here’s the big question: How can we be more like a torpedo (and conversely, less like a noodle) when we swim? The key to doing this is to manage the rotation of our body from side to side. While Body rotation is a natural offshoot of the way we move our arms when we swim freestyle, it can also be managed so that when our hip rotates down, it stabilizes our body into a more rigid form.
When this happens, the down-rotated “edge” of our body becomes our Center of Pressure. This allows the force that we generate as we stroke and kick to concentrate and act through that edge. If we hold this edge throughout our stroking movement, we can increase the distance (length of our stroke) that we generate force in the water. This means that we can increase the work we do (distance we travel forward with every stroke), without increasing the amount of force we generate.
This translates to two simple goals when it comes to rotation: 1: We need to hold our center of pressure along the edge of our body for as long as possible during the stroke and 2, We need to make sure that we rotate neither too little, causing poor center of pressure, or too much, causing us to sink.
Generally speaking, this means that your hip should rotate down as your arm enters the water, and that you should hold that down position as long as possible during your underwater stroking movement. It also means that you must ensure that you rotate between 20 and 45 degrees relative to the surface of the water.
The best way to work on stabilizing and maintaining your rotated position during your stroke is to use 1-arm Rotation drill. This drill has two key benefits: 1, it will allow you to feel what it is like to hold your rotation through your stroke, and 2, it makes it very difficult to under or over rotate your body.
Start by floating in a horizontal position in the water, with one of your arms held straight and tight to your side. Extend your other arm forward in front of your shoulder. Take a quick stroke, and just as your arm reenters the water push your hip down. It is not necessary to move it very far; you should only feel like it moved an inch or two. As you do this, you should feel the edge of your body press down as your arm extends forward. Take your next stroke, focusing on maintaining that center of pressure with your hip for as long as you can during your stroke.
As you do this drill, you should feel like you are able to strongly push your body forward against the position of your arm. Once you can, the next step is to build this drill into a workout that will allow you to focus on stabilizing your rotation as you swim.
Focus: Stabilizing and Maintaining Body Rotation during underwater stroking movement
Repeat 4x (Alternate Arms on 25 Drill)
25 yds. 1-Arm Drill
50 yds. Freestyle maintaing good body rotation
25 yds. 1-Arm Drill
Tip: Like anything else in swimming Freestyle, maintaining a stable center of pressure isn’t the only way to harness the power of your bodies’ rotation. Nevertheless, it will stabilize your bodies’ position in the water, allowing you to travel farther forward with each stroke. This will reduce your stroke count, and help you to swim faster.
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