Underwater (Double leg) Kick

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  • #3498
    Avatarjared
    Participant

    Just curious how others are handling this particular element of swims.

    Rushall’s technique macrocycle advocates a narrow fast kick with a still upperbody. This flies in the face of conventional wisdom (which doesn’t bother me at all), but also what the best swimmers in the world are doing and what seems to be more effective in my swimmers (a wider kick trying to generate more propulsion and slightly more upper body movement).

    Obviously the more still your upper body is the less resistance you are working against, but kicking at a lower tempo will also reduce resistance right? And if you can travel more distance per kick you can do less kicks which also would reduce the resistance you are working against.

    Just curious to hear some others thoughts. To me it seems like there is a happy medium on it, or perhaps a large variation between what is ideal on an individual basis.

    #3502
    Avatardoc
    Participant

    Jared,
    Think of fish and how they move. When just swimming lazily in the pond they have wide-sweeping movements, not in any hurry. But as soon as there’s a threat things get real narrow and fast in a hurry.

    I tell my kids you only have as deep as you are thick in the water. so, maybe 12-18 inches. Once you get outside that range you increase drag (the easiest way to go faster is reducing drag).

    I don’t like using the word kick. It implies to me up/down movements and we want the water to flow, not try and beat it into submission.

    Are you trying to replace strokes with underwater kicking? If so there are problems with kick tempo and matching stroke tempo and distance traveled.

    Just some rambling thoughts,

    Doc


    ? I child proofed my house and they still get in ๐Ÿ™‚

    #3504
    Avatarjared
    Participant

    Are you trying to replace strokes with underwater kicking? If so there are problems with kick tempo and matching stroke tempo and distance traveled.

    Could you elaborate on this for me? Or point me in the direction of some resources?

    Always interested in your perspective.

    #3505
    Avatardoc
    Participant

    Jared,
    The best advice is if you can still find it is watching the Youtube video by Bob Gillett (RIP) “Why kicking underwater is faster”. We worked on this from about 1992 to 2004ish. Mainly used my guys to increase the “N” and teaching sequences.

    Issues, tempo trainers for each swimmer, and the monofins for 1/2 the group. We had that equipment for free. I wouldn’t do it now with tempo trainers at 60+$ and fin at 65$. You can get away with just a tempo trainer and ditch the fin as I think there are better ways to introduce the undulation action needed and give the swimmer better sensations. It’s also a “crutch” for many of the swimmers and distorts the sensations of flow.

    I’ll look through my old notes and if I come up with anything more I’ll post.

    Just my thoughts
    Doc


    ? I child proofed my house and they still get in ๐Ÿ™‚

    #3506
    Avatarjared
    Participant

    cheers doc,

    As insightful as always.

    I’d love the chance to pick your brain about a lot of this stuff. I’m running a small program across the world from you (and I’m a young coach in my mid 20s), but I’d like to let you know that you have had a tremendous influence on my program (which has produced state champions in our little corner of the map). You definitely have given me a lot to think about over the last 2 years at the very least.

    #3507
    Avatardoc
    Participant

    Jared,
    Thank you for your kind words.

    My email is oldrecondoc@gmail.com

    Have a Happy New Year and stay well!

    Doc


    ? I child proofed my house and they still get in ๐Ÿ™‚

    #3509
    Avatarryanupper
    Participant

    Rushallโ€™s technique macrocycle advocates a narrow fast kick with a still upper body. This flies in the face of conventional wisdom (which doesnโ€™t bother me at all), but also what the best swimmers in the world are doing and what seems to be more effective in my swimmers (a wider kick trying to generate more propulsion and slightly more upper body movement).

    He was more than likely advocating for minimizing movements during the era when everyone was doing full-body super-undulation. That style has faded away. Kick from the hip and keep the upper body “quiet” and streamline if not still. Sprinters can get away with moving the upper body more if the tradeoff is generating more force from the kick than the frontal drag from the upper body’s drag shadow.

    As for the feet distance, Rushall didn’t do a ton of writing on turbulence. He was mostly focused on drag reduction and combating the lift force theory (which he was 100% correct on, we aren’t a wind-powered hydrofoil). From my own testing, the feet should be about hips distance apart. This is backed by research in a number of other areas: 1) injury reduction and efficiency in cycle pedaling where pedals contain spacers to align with the hips, 2) separating the fingers by 5-6 mm during the swim pull to increase the compression surface of the hand (increasing the turbulent area around the hand) and 3) the law of least resistance – when an object travels through a medium it will find either the shape or path of least resistance.

    What all this means is that when the feet are together they are probably pressing against mostly the same water and it is flowing around a smaller object. When the feet are separated enough there are 2 turbulent pockets that compete for flow around the feet. Widening the feet outside of the hips creates a muscular or biomechanical inefficiency and increases the leg drag shadow.

    What I notice in my own training is that when my kick gets tired the feet start to get closer together to use the same pocket of pressure which allows them to travel through the water easier. This is just like the wrist bending back or the elbow “dropping” during the pull when you start to fatigue. A vertical forearm with a stiff wrist is harder to maintain but also generates more force and thus more power.

    As for underwater swimming, there has been a lot of research on this. Push off the wall at 12-18 inches, streamline glide at a 10 degree down angle for 4-6m to about 3-4 feet underwater (depending on pushing power), start kicking when you feel your speed drop to your kicking speed, then rotate to a 5-10 degree up angle with smallish-fast kicks. You should feel like the kicking and buoyancy are accelerating you to the surface.

    Ryan

    #3510
    Avatardoc
    Participant

    I know the one study that looked at this. It showed the reduction of drag at certain levels of water depth and the 3-4 feet had the least drag coefficient, that’s great, unrealistic but great. Because if you are 3-4 feet down, then you have to come back up 3-4 feet. Think about that. I think it’s much simpler to just have some degree of mastery in running the “boundary layer”, 18-24 inches (I think in the study, if you did the conversion it was 16-18 inches, which had the second best coefficient) underwater holding that line with as close to perfect intersect, line moving FORWARD at breakout, no vertical travel! i.e. floating/poor angle back to surface because they were to deep. I think with the majority of kids we work with would be well ahead of the game.

    Just more thoughts,

    Doc


    ? I child proofed my house and they still get in ๐Ÿ™‚

    #3511
    Avatarryanupper
    Participant

    I know the one study that looked at this. It showed the reduction of drag at certain levels of water depth and the 3-4 feet had the least drag coefficient, thatโ€™s great, unrealistic but great. Because if you are 3-4 feet down, then you have to come back up 3-4 feet.

    I’m sure we are thinking of the same study. I think Rushall commented on it. I would say 3-4 feet isn’t that deep if you look at the center/bottom of your torso to the surface – your upper body thickness is probably 6-8 inches deep.

    I see it as an energy conversion and conservation problem. I have the most energy pushing off the wall and I can hold a streamline to conserve that speed. This is the best time to get a little deeper and into a lower drag area without expending more energy. I have noticed when the underwater kick is strong, that I feel like I’m accelerating to the surface maybe with help from buoyancy.

    Caveats: If at any point you feel slower underwater than on the surface somethings not working for you and you’re better off just getting to the top after a turn. Also, I don’t think this is going to get studied anytime soon so I would use whatever is fastest for each athlete. I think a higher level athlete can get away with adding a little “arc” to extend their underwater distance but most will benefit from fundamentally simple underwater streamlines with kicks to the surface.

    For fun debate, Dressel underwater: https://youtu.be/wy6HzIwKL9A?t=58

    #3512
    Avatarryanupper
    Participant

    Oh, I don’t have time to find this but there was also something about in order to maintain depth while moving forward you need to angle your body down 3-4 degrees anyway. I think this was to counteract buoyancy. If this is the case it means you would be applying some energy in the vertical component just to maintain depth.

    #3515
    Avatardoc
    Participant

    Not exactly on kicking. But the importance of core tension or Posture-Line-Balance. Which have a huge impact on kicking and swimming.

    Old Dive and Glide “The Plunge for Distance”

    Detailed Swimming on YouTube to see video
    Caeleb Dressel 24.9m or 81ft

    Holds good core tension on entry and during glide phase. Appears to run the LINE or BOUNDARY LAYER 18-24″ to a perfect intersect with surface keeping the “LINE MOVING FORWARD”

    Swimming World article on “The Plunge For Distance” in early 1900s
    WR in 1902 was 79ft 3inches

    Holds good core tension during glide phase. Nice LINE and BALANCE

    The more we think how things have changed, the less they really have.

    I guess it pays to be old and still have a memory ๐Ÿ™‚

    Doc


    ? I child proofed my house and they still get in ๐Ÿ™‚

    #3516
    Avatardoc
    Participant

    Oophs, my bad. if you’re interested you can find the picture at the Swimming World article on “The Plunge”

    Doc


    ? I child proofed my house and they still get in ๐Ÿ™‚

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