The two inferior techniques largely rely on pushing down against the water

Saturday, October 16th, 2021

Alex Hutchinson reviews a recent study on the physiology of treading water efficiently:

They put 21 volunteers, all experienced water polo players, synchronized swimmers, or competitive swimmers who self-identified as water treading experts, through a series of physiological and cognitive tests while performing four different styles of treading. The verdict: some techniques really are substantially better than others.

The four techniques are as follows:

  1. Running in the water: This one is pretty self-explanatory. Hands and feet are moving up and down in a running-like motion.
  2. Flutter kick: Your hands are sculling back and forth along the surface of the water, while your legs do a flutter kick.
  3. Upright breaststroke: Your hands are still sculling along the surface of the water, but your legs are doing the distinctive frog kick of the breaststroke.
  4. Eggbeater: It’s similar to the upright breaststroke, with the key difference that your legs are kicking one at a time instead of synchronously, producing an eggbeater pattern of alternating circles with each leg.

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There were clear differences in how efficient the different techniques were, with running and flutter kick performing equally poorly, and upright breaststroke and eggbeater performing equally well. This pattern showed up in every outcome measure.

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Normally VO2 measurements are adjusted for weight, since heavier people burn more energy — but in this case, wet weight was used to also account for differences in buoyancy.

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The two inferior techniques largely rely on pushing down against the water to move the body upward. This has two problems: water is too thin to provide much support, and even when the pushing works you get a lot of wasted up-and-down motion. The two better strokes, in contrast, involve lateral movements of the arms and legs: your cupped hand acts like an airplane wing or sailboat sail, generating lift forces perpendicular to the plane of motion. This is more efficient than pushing on the water, and produces less wasted vertical bobbing.

There’s one key difference between upright breaststroke and the eggbeater: in the former, your legs are kicking outward at the same time, while in the latter they’re alternating. This means that breaststroke produces some of that undesired up (when you kick) and down (between kicks) motion — and that effect is exacerbated if you stop sculling with your hands. In the eggbeater, there’s always one leg moving, so you get a smoother, more continuous lift that can keep you up even without your hands. The study didn’t test anything that required using your arms — but if you want to throw a water polo ball, strike a fancy pose during your synchro routine, or signal frantically to a passing ship that you need rescue, eggbeater looks like a much better bet.

Comments

  1. RMJ Tools says:

    I don’t quite understand the ultimate purpose of this testing Is for. If it is to determine the most efficient and easiest way to stay alive in water as in not to drown then the old fashioned “Drown Proofing “ I learned in SCUBA school is a better alternative. https://en.wikipedia.org/wiki/Drownproofing

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