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Thread: Asafa slow motion block start

  1. #21

    Re: Asafa slow motion block start

    Quote Originally Posted by lkh View Post
    See Dr. Pfaff above from 1:30-2:00 in the video.



    I notice in Asafa's latest 9.84 that he did not get off to THIS kind of start:

    https://www.youtube.com/watch?v=Sw2qmRPZOO4
    I think Gateshead 9.77 may have been better.

  2. #22

    Re: Asafa slow motion block start

    Quote Originally Posted by T-Slow View Post
    I can tell you of an experience I had on a training camp earlier this year. I had a guy come with me that basically heel cycles right out of the blocks. We found that the time from first motion to first contact was relatively unchanged regardless of low heel recovery or high heel recovery. However, his contact time on step one was reliably reduced by 3 one hundredths of a second with a low heel recovery. Interesting stuff! Play around with it and see what you find. I've seen up to 0.10 saved on the first three steps.

    "The start is way more important than we thought!" was what I saw Ralph Mann say in December 2013.

    Charlie knew that 30 years ago.

    Just because CF and Mann differ somewhat on biomechanics (due to the availability of force blocks, and high speed cameras that fit in your pocket) doesn't mean CF was wrong. He had the key ideas correct (work on accelerating a lot, and get back on the ground and push before everyone else) and his athletes were kicking the crap out of everyone at accelerating way before anyone else knew what he was up to. I mean in Seoul the race was literally over at 3 metres- and this fact is what convinced me Mann was onto something.
    Look at the chart on this page:

    http://speedendurance.com/2008/12/02...ide-frequency/

    Asafa ran the first 10m the same as Carl and Ben was 0.06 ahead of Asafa at 60....but at the end of the race Asafa went faster, and that wasn't the fastest Asafa ever ran. But I think this makes the point that Pfaff is trying to make. For me personally, what works best is the Steve Francis way ("long, longer, longer yet"--from the youtube "Asafa Prepares For Sprinting"): Getting a hard push from the blocks, concentrating on pushing power for the first 4-6 strides, then beginning to extend, which is the same thing I see Asafa doing (comes from the same coach).

    But my impression is that low heel recovery comes as a second order result from pulling sleds. And that's what you do if you want strong acceleration--you pull a sled or sprint up a steep hill. But if you decide you need low heel recovery because people who pull sleds have low heel recovery and you concentrate on heel recovery instead of the thing that caused the heel recovery, are you simply messing up your biomechanics and making the second half of your race slower like Dr. Pfaff talks about? One of Charlie's favorite phrases: Paralysis through analysis.

    Another thing I'm noticing, and I noticed with Bolt back in 2009, is tall sprinters ending the drive phase earlier and getting their legs extended...and going faster by getting into MaxV sooner. I see Asafa this year getting his head up just before the 4.0 point, compared to staying in the drive phase longer before and getting fully up around 5 seconds.

  3. #23
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    Re: Asafa slow motion block start

    Quote Originally Posted by T-Slow View Post
    Hey James,

    Great to see you back posting! I did see his 9.84, and he looks great. He is supposedly training with his brother Donovan full time in Austin, and clearly he knows what he's doing.

    In addition, I was surprised to see Gatlin run a personal best today. I didn't think he had a 9.74 in him!
    I just watched the 9.74. What a testament to latent abilities for him to perform at this level following the multi-year competitive layoff. Interesting that he is one that sacrifices complete extension during the initial acceleration and has been an exceptional accelerator; while Tyson Gay is also notorious for sacrificing complete extension (forcing the torso forward) during the initial strides yet, in contrast, has never been exceptional over the first 20-30m.

  4. #24
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    Re: Asafa slow motion block start

    Quote Originally Posted by lkh View Post

    But my impression is that low heel recovery comes as a second order result from pulling sleds. And that's what you do if you want strong acceleration--you pull a sled or sprint up a steep hill. But if you decide you need low heel recovery because people who pull sleds have low heel recovery and you concentrate on heel recovery instead of the thing that caused the heel recovery, are you simply messing up your biomechanics and making the second half of your race slower like Dr. Pfaff talks about? One of Charlie's favorite phrases: Paralysis through analysis.
    Even more than sleds, the elastic contraptions that athletes (including Gatlin) attach to their ankles, thighs, wrists, upper arms completely alter natural kinematics by inhibiting heel recovery and forcing front side arm action.

    Well said regarding heel recovery being a symptom of other causalities versus an end unto itself.

  5. #25

    Re: Asafa slow motion block start

    I would encourage you to read Ralph Mann's "The Mechanics of Sprinting and Hurdling" before dismissing Asafa's technique. His max velocity mechanics in his 9.72 run in Lausanne are what I would argue are the best ever. Ralph has studied virtually all the top US sprinters for the past 25 years, and he has a very clear model of what his data shows is optimal technique. Regardless of what you think of Mann, you should own his book.

    I don't think it is fair to state that evidence of Bolt's heel to butt technique on pull-through is superior to Asafa's shin parallel to ground on pull-through. You are talking about two guys with levers of different lengths. If I had to choose, I would choose Asafa's technique every time over Bolt's, but I would choose Bolt's levers. Mann's data suggests you will save 0.005 per stride with a parallel shin pull-through. Bolt doesn't need to experiment with this, as he is the fastest.

    I will tell you that I have spent time with two elite US coaches in the past year, and they have each incorporated Mann's technical model with very good results. I can tell you that when Mann initially presented his findings a few years back, there was MAJOR resistance from top US coaches. A few years later, they are all using it. That should tell you something.

    With regard to start data and Mann, he found what Charlie figured out 30 years ago: "He who is not on the ground cannot push." Whoever gets their foot down on the ground to push again first (and whose centre of gravity isn't in front of them) is going to be the fastest starter. While Mann trashes the jumpstart as inefficient overall (and correctly so- who since Ben has had success with it?), the reality is he espouses the same big picture advice that Charlie did: get back on the ground and push. Ben made the jumpstart work for him because he was back on the ground pushing again while everyone else was still floating in mid-air with their long, slowass pushes
    .


    I am familiar with Manns research however you are going off on a tangent.The initial argument was based on Asafa first few strides, which is that the toe drag is not efficient. Whilst there is a need to minimse flexion in the first few stride , dragging the feet is not the optimal technique.

    Do I have any peer-reviewed evidence? Nope. But science is an inherently conservative field which trails practical experience by up to 30 years, so I don't have time to wait for that.


    You are making some very broad generalisations about the entire field of science. I am a researcher in medicine however my background was previously sports science. I think a little bit of context will be helpful. Thirty years ago in medicine a number of drugs were prescribed on the basis of practical experience by doctors, they were also approved on the basis of uncontrolled trials. However, later when probably controlled studies were designed it was found out that these drugs were actually highly toxic with no therapeutic benefit. This is the worst possible outcome when patients die because doctors prescribed medications on the inherently bias nature of experience. The take home message is that well controlled clinical trials exceeds practical experience , especially in the field of medicine.


    There is high quality evidence in literature however you need to spend the time reading it.

  6. #26

    Re: Asafa slow motion block start

    Quote Originally Posted by lkh View Post
    See Dr. Pfaff above from 1:30-2:00 in the video.



    I notice in Asafa's latest 9.84 that he did not get off to THIS kind of start:

    https://www.youtube.com/watch?v=Sw2qmRPZOO4

    Powell also ran faster early this season than he did back in 2010 when he ran that blazing start in Rome, so I'm wondering if overemphasis of things like toe drag that are going to have relatively minimal effect on time amount to wasting energy on what Dan Pfaff describes as too rapid acceleration for your genetics that cost you more time later. I think Pfaff is really talking about things like shortening your stride to get the absolute fastest acceleration, but that might not be the only thing that costs you later.

    In terms of real numbers, what do you really get from toe drag? And how much energy are you wasting from the biomechanics standpoint?

    Dan makes some excellent points. Just some further points, greater ground reaction forces causes greater displacement through the flight phase. This means during max velocity that stride length will be greater for the fastest sprinters, this is well documented in the literature.

  7. #27

    Re: Asafa slow motion block start

    Quote Originally Posted by Chris6878 View Post
    the 2 races ive seen from him this year, he has not toe dragged at all
    One of the reasons why he has already run 9.84.

  8. #28

    Re: Asafa slow motion block start

    Gatlin took 41.5 strides when he ran 9.77 in 2006. Last year, he took 43.0 strides to run the same time, and this year it was 43.5 strides for 9.74. He seems to have worked on shortening his stride length probably to avoid overstriding.

    After his runs at world relays, this result should not come as a surprise.

  9. #29

    Re: Asafa slow motion block start

    Quote Originally Posted by lkh View Post
    Look at the chart on this page:

    http://speedendurance.com/2008/12/02...ide-frequency/

    Asafa ran the first 10m the same as Carl and Ben was 0.06 ahead of Asafa at 60....but at the end of the race Asafa went faster, and that wasn't the fastest Asafa ever ran. But I think this makes the point that Pfaff is trying to make. For me personally, what works best is the Steve Francis way ("long, longer, longer yet"--from the youtube "Asafa Prepares For Sprinting"): Getting a hard push from the blocks, concentrating on pushing power for the first 4-6 strides, then beginning to extend, which is the same thing I see Asafa doing (comes from the same coach).

    But my impression is that low heel recovery comes as a second order result from pulling sleds. And that's what you do if you want strong acceleration--you pull a sled or sprint up a steep hill. But if you decide you need low heel recovery because people who pull sleds have low heel recovery and you concentrate on heel recovery instead of the thing that caused the heel recovery, are you simply messing up your biomechanics and making the second half of your race slower like Dr. Pfaff talks about? One of Charlie's favorite phrases: Paralysis through
    analysis.

    Another thing I'm noticing, and I noticed with Bolt back in 2009, is tall sprinters ending the drive phase earlier and getting their legs extended...and going faster by getting into MaxV sooner. I see Asafa this year getting his head up just before the 4.0 point, compared to staying in the drive phase longer before and getting fully up around 5 seconds.
    www.youtube.com/watch?v=oGhF1STB3mI


    -if we go back to the texas relays 100's the oregon training dual, bailey and morris. Morris ran 9.8x windy
    before the kiryu race, but he really powered the first 20m such that he got there in 15 contacts, and then had the strength to maintain the frewuency and momentum to cover the 100m in 44contacts.

    -also it always seems to me that a skinny dude in their first 2-3years of formal sprint training(age 17-25 or thereabouts), has the ability to muscle some long initial srides with that skinnier(less muscled frame) build, and not get too dinged up. It makes me think that at the younger adult ages, one should run with as much techniques as they could handle and push the envelope (within reason) in each of respected techniques(power stride length, power stride frequency, speed endurance stride length, speed endurance stride frequency, so on and so forth)(even co-contraction quad n hammy stride length maybe lol)

  10. #30
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    Re: Asafa slow motion block start

    Quote Originally Posted by Sharmer View Post
    .


    I am familiar with Manns research however you are going off on a tangent.The initial argument was based on Asafa first few strides, which is that the toe drag is not efficient. Whilst there is a need to minimse flexion in the first few stride , dragging the feet is not the optimal technique.

    You are making some very broad generalisations about the entire field of science. I am a researcher in medicine however my background was previously sports science. I think a little bit of context will be helpful. Thirty years ago in medicine a number of drugs were prescribed on the basis of practical experience by doctors, they were also approved on the basis of uncontrolled trials. However, later when probably controlled studies were designed it was found out that these drugs were actually highly toxic with no therapeutic benefit. This is the worst possible outcome when patients die because doctors prescribed medications on the inherently bias nature of experience. The take home message is that well controlled clinical trials exceeds practical experience , especially in the field of medicine.

    There is high quality evidence in literature however you need to spend the time reading it.
    The toe drag is a motor learning approach to teaching low heel recovery. Toe dragging isn't absolutely necessary I don't think, but low heel recovery is an indication that your pelvis is in a neutral position, and that you are using your spine rather than spinal erectors to direct force. That is very desirable in my opinion. The way Ralph teaches it is not optimal unless you are super elite and are a kinesthetic genius who can turn vague cues into something sensible. For the average athlete, it's a disaster.

    Low heel recovery is faster than butt-kicking out of the blocks in every test I have conducted or have seen others conduct. Not everyone agrees- Dan Pfaff argues that it puts too much strain on the hip flexors and is intolerable for some. Most other US pro coaches teach some form of low heel recovery though.

    The generalization I made about science was a fair one I think. There is no money to be made studying track and field technique, so I won't hold my breath for a peer reviewed study. I'm not suggesting that peer reviewed studies aren't useful- they just take forever to happen, and I'm not going to put my coaching on pause until someone studies the start.
    Last edited by T-Slow; 05-17-2015 at 09:22 AM.

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