Video: What makes a swimmer efficient?
by Terry Laughlin

Posted on November 23rd, 2010

If you want to really understand what happens in swimming, you can find no better source than the TI Discussion Forum. Here’s practical insight on the question Should taller swimmers take fewer strokes?

Alex asked: Why is it that tall people are supposed to take fewer strokes per pool length? I’m 190cm(6’3″). Why would that translate to, say, 2-3 strokes less than someone who is 160cm (5’6″)?

TI Coach Suzanne Atkinson replied: A height advantage multiplied by many strokes, adds up quickly. 30cm in your example x just 10 SPL = 300cm, or 2 full strokes. 30cm x 15 SPL = 450cm or 3 full strokes.

Richard Skerrett added: I believe the wingspan ( fingertip to fingertip) is also an important dimension as is the “ape factor” — the ratio between wingspan and height. Hand and foot size are also probably significant.


Nevertheless, in the world of ordinary swimming, a short, slightly built swimmer who is more efficient will usually go faster than a long muscular one and in fewer strokes as well. At a recent meet a friend pointed out to me a female backstroker who was taking seven strokes to do 25m while warming up. I take about 30, so I was impressed. She was a lot faster as well.

Height is only one factor – and not the most significant – in influencing SPL. The more significant factor is skill. Among the components of skill, Balance will influence an individual ‘efficiency potential’ the most . . . Then Streamlining . . . Then Propulsive Effectiveness – which encompasses hand and foot size mentioned by Richard.

Because Balance is the single most important factor influencing SPL potential, how height is distributed must be part of the equation.

The best illustration is that TI Coach and CEO Shinji Takeuchi, at 170 cm (5’7″), can swim 25m in 9 strokes (see video below), while I, at 183cm(6’0″) am hard pressed to do it in fewer than 12 strokes. Our height differential alone would predict I should take two fewer strokes. So why do I take three more?

The reason is Height Distribution. Virtually all of our 13 cm height differential is below the hips. Since our torso’s are approximately the same length, but my legs are far longer, Shinji has a balance advantage that more than compensates for my height advantage when it comes to stroke efficiency.

Where my height does bring advantage is speed potential — in long-axis, but not short-axis, strokes. More height means lower drag as speed increases. This advantage increases markedly as we both get faster, since drag increases exponentially as speed goes up. In fact, I once heard a swim researcher say that the main reason age group swimmers improve is simply because they grow taller each year. At the time this came as a bit of a blow to my ego, as I was coaching adolescents at the time and flattered myself my superior coaching was the reason they got faster.

While watching Shinji in the video below, notice (a) how perfectly horizontal he is; (b) how small and easy his kick is; and (c) how unhurried his recovery is. All are marks of Balance. To swim raise your efficiency toward Shinji’s level, do as he did: Practice the balance exercises from Lesson One of the Self-Coached Workshop DVD (or Lesson One of the Easy Freestyle DVD).

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10 Responses to “Video: What makes a swimmer efficient?”

  1. Liz says:

    I am glad this topic came up. My goal right now is to swim 25 yards with 16 individual arm strokes. Currently is hovers around 19 with a time of 0:50 for 50 yrds (standard workout). My height is 5’1″ my arm span (reaching out side to side) is 6′ 2″. My hands are small like a kid and I wear a 5.5 size shoe and 50% of my height in my legs. Based on my experience–and this article seems to confirm it–it looks like I have my work cut out for me. There is always something to work on!!

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  2. Liz
    At 5-1, 16 to 18 strokes for 25 yds would be pretty solid efficiency. So if you can improve from 19 to 18 you’d be doing well. Before trying to push lower, I’d suggest you do the following
    1) Maintain 18-19 comfortably for incrementally longer repeats. Sets like (25-50-75-100) or (4×25+3×50+2×75+1×100) work well for this.
    2) On repeats shorter than 100, try to swim incrementally faster at that SPL.
    Give your nervous system time to adapt to the new movement pattern it takes to cross the pool in 18. And your physiology to adapt to the ‘work’ requirement of doing so. That will give you a foundation to succeed at the next step.

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  3. Liz says:

    Thanks for the suggestion–will keep you up to date. Have a Merry Christmas!

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  4. Liz says:

    I thought my arm span looked weird: it is 62 inches!!! not 6 foot 2 inches!!! those darn typos!!!

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  5. Bea Webster says:

    Thanks for sharing the video! Wow, it is beautiful to watch. I am a newbie and just started with the Video Easy Freestyle so there is a lot I don’t understand. But it is amazing how much enjoyment I am getting out of my swimming. Thanks

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  6. bobby vee says:

    Are you sure that’s a standard length pool? ;-) It looked like Shinji took about 20 seconds to cover the distance in only 9 strokes. I timed his stoke speed at ~1.6 sec/stroke. So he is both “moving” and using very few strokes. Very impressive.
    Does he compete?
    Just out of curiousity, I checked out a Michael Phelps video (http://www.youtube.com/watch?v=ax77_hHq9Dc). He takes 23 strokes across an Olympic length pool (just counted it) at ~.88 sec/stroke.

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  7. Shinji does compete, though infrequently. He hopes to compete more often in the future, but for now his greatest priority is spreading TI globally.

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  8. bobby vee says:

    Love TI. Started it a year and a half ago preparing for a Tri. I was never a swimmer and was nervous about the swim leg. I took a TI weekend class and After 4 weeks of training I finished the swim leg fresh, with a big smile on my face. I have done eight Triathlons since then (including a half IM) and the swim is now one of favorite parts. I always give full creds to TI. Your method is beyond compare!

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  9. Congratulations Bobby and thanks for sharing your enthusiasm with us.

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