Is Sprint Technique Training Necessary?

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    mcdowl on #59440

    This is just me trying to piece together some jumbled thoughts in writing… Weyand found that the main determining factor for faster sprinting is force applied to the ground… Barry Ross then goes on to devise a training program based upon this idea. Barry Ross's method attempts to maximize the amount of force an athlete can apply to the ground, and excludes technique as essentially irrelevant… Now, if you did a similar study comparing ground forces and movement speed in elite and beginning shot putters while throwing, it doesn't seem that unlikely that you would find that the main determining factor for further throws was force into the ground, and that speed of movement was not significantly different. Would you then conclude that technique plays no role in shot putting?? But, isn't this an absurd conclusion? Doesn't it completely disregard extremely important body positioning factors that occur in the non support phase of throwing the shot that improve leverage and the ability to apply force at relevant angles etc? 

    Mike Young
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    Mike Young on #59441

    McDowl-
    Excellent analogy with the shot put example…it really does show absurd the 'either-or' viewpoint is.

    ELITETRACK Founder

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    bear on #59442

    Actually, that is a very bad analogy  :bigsmile:

    Barry Ross

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    Daniel Andrews on #59443

    Actually, that is a very bad analogy  :bigsmile:

    Barry Ross

    Actually, it's a very good example Mr. Ross.  Force applied to the ground from an improper angle of attack would result in different physical mechanics.

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    Patrick Pyle on #59444

    I think this fits this topic – Seagrave said there are four stages that an athlete goes through when learning a new skill

    1- Unconscious Incompetence – The athlete is not thinking because they have never been told to think about anything, and are not very good at new skills. He said that he tells his athletes that it is better to look foolish in front of their teammates in practice and get better at the skills than to get embarrassed in front of an audience.

    2- Conscious Incompetence – The athlete is starting to understand the skill and try to execute it but are not very good at it yet.

    3- Concious Competence – The athlete has developed the skill but cannot perform it automatically and mindlessly. In this stage, unconcious action returns one to previous bad habits.

    4- Unconcious Competence – The skill has become automatic and performed perfectly with no concious effort. Attainment of this level takes not only practice, but mental imagery and rehearsal. It can take up to 500 of practice to achieve unconcious competence with a skill.   

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    bear on #59445

    Actually, it's a very good example Mr. Ross.  Force applied to the ground from an improper angle of attack would result in different physical mechanics.

    It's a bad analogy for several reasons. As a long time throws coach, I fully understand the mechanics of the shot put so I know that ground contact time is much longer than when sprinting. The shot requires chemical muscle mechanical work primarily and elastic energy secondarily. The longer ground contact allows for more volitional force application.

    Sprinting is primarily elastic with minimal chemical work. The reason this is so is because ground contact time is very small and humans cannot create the measured forces within the time frame they are applied. Elite runners can exceed 3 x bodyweight on force plates when running at top speeds. It's possible they can do even more.  So a 150 lb sprinter will register a peak of 450 lbs or more on the force plate just prior to halfway through the stance then force rapidly declines to almost zero before toe-off. The runner cannot create 450lbs of force in approximately .04 seconds on one leg.
    When locomotion experts talk about the athlete's force application, the phrase generally used is " force to offset gravity". The runner applies isometric force to withstand hitting the ground without collapsing.
    Despite Mike's insistence at the beginning of this thread, not only do I understand physics as it applies to running and jumping, I'm also a friend of Peter Weyand and talk to him regularly. I don't misuse or misunderstand the study. I know full well what it says and what it means.
    It's the sprint "guru's" that keep spitting out unscientific information. This comes from an addiction to kinematics and a lack of understanding physics and its affect on sport.

    Barry Ross

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    Daniel Andrews on #59446

    The analogy is of "technique being of important" which is a cross of biomechanics and motor learning.  To me, it's not an analogy of they being similar movements.  I don't care how much force you cause to be applied to the ground, if the application of a force is wrong the system breaksdown.  In this case the system is a spring-mass system.  I have been stating for a while now if the angle of attack is wrong (essentially how far in front of the COM the foot touches down) that gct is increased regardless of speed (think inverted pendulum) and impulse is reduced with a reduction in stride length because of the dissipation of elastic energy that is not returned.  The problem of gct is not just related to leg stiffness and vertical stiffness.  As mike stated force is a vector, and if that vector is wrong, I don't care how stiff your body and legs are you will not have optimal mechanics.

    Mike Young
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    Mike Young on #59447

    I think this fits this topic – Seagrave said there are four stages that an athlete goes through when learning a new skill

    1- Unconscious Incompetence – The athlete is not thinking because they have never been told to think about anything, and are not very good at new skills. He said that he tells his athletes that it is better to look foolish in front of their teammates in practice and get better at the skills than to get embarrassed in front of an audience.

    2- Conscious Incompetence – The athlete is starting to understand the skill and try to execute it but are not very good at it yet.

    3- Concious Competence – The athlete has developed the skill but cannot perform it automatically and mindlessly. In this stage, unconcious action returns one to previous bad habits.

    4- Unconcious Competence – The skill has become automatic and performed perfectly with no concious effort. Attainment of this level takes not only practice, but mental imagery and rehearsal. It can take up to 500 of practice to achieve unconcious competence with a skill.   

    These are basic motor learning concepts….all proven by research (albiet using different terminology).

    ELITETRACK Founder

    Mike Young
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    Mike Young on #59448

    Barry welcome to the board. I'm glad you joined on here.

    It's a bad analogy for several reasons. As a long time throws coach, I fully understand the mechanics of the shot put so I know that ground contact time is much longer than when sprinting. The shot requires chemical muscle mechanical work primarily and elastic energy secondarily. The longer ground contact allows for more volitional force application.

    The source of the force is irrelevant for the purpose of this discussion. I am speaking from a purely mechanical sense….the most basic and fundamental understanding of kinetics….and this is where you go woefully off course. To say that the direction of the force vector does not matter is absurd. If you are in fact arguing this issue (that direction of the force vector doesn't matter) please let me know and we'll discuss.

    Sprinting is primarily elastic with minimal chemical work.

    What in the world is 'chemical work' and how does this apply to the discussion of force vectors.

    The reason this is so is because ground contact time is very small and humans cannot create the measured forces within the time frame they are applied.

    No argument here. In fact, I argue that because ground contact time is so short one must PREPARE for it while still in flight in order to position the limbs in the most appropriate way to apply the largest possible forces in the appropriate directions.

    Elite runners can exceed 3 x bodyweight on force plates when running at top speeds. It's possible they can do even more.  So a 150 lb sprinter will register a peak of 450 lbs or more on the force plate just prior to halfway through the stance then force rapidly declines to almost zero before toe-off. The runner cannot create 450lbs of force in approximately .04 seconds on one leg.

    No but they clearly can in 0.8-0.10s….the ground contact time for the best sprinters in the world. 

    When locomotion experts talk about the athlete's force application, the phrase generally used is " force to offset gravity". The runner applies isometric force to withstand hitting the ground without collapsing.

    Do you disagree with this point? I'm not clear by what you've said.

    Despite Mike's insistence at the beginning of this thread, not only do I understand physics as it applies to running and jumping, I'm also a friend of Peter Weyand and talk to him regularly. I don't misuse or misunderstand the study. I know full well what it says and what it means.

    I too know Peter. We've corresponded via email and have met on 2 occassions. He has actually contributed several articles to this site. I also frequently correspond with Dr. Ralph Mann, USATF sprint biomechanist for the last 20 years.

    It's the sprint "guru's" that keep spitting out unscientific information. This comes from an addiction to kinematics and a lack of understanding physics and its affect on sport.

    I am in no way a 'sprint guru' and would argue that I have a fairly decent understanding of mechanics (USATF biomechanist for past 5 years; biomechanics PhD). Kinematics beget kinetics. This is a fundamental concept of biomechanics. Please address the following questions:
    1. Does the direction of force applied to the ground matter at all?
    2. What is chemical work?
    3. Does the runner need to offset the effects of gravity?
    4. What is more important to sprinting- concentric strength or eccentric strength or some other form of strength?
    5. How is "elastic force" produced?

    ELITETRACK Founder

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    Patrick Pyle on #59449

    [quote author="padow" date="1168905996"]
    I think this fits this topic – Seagrave said there are four stages that an athlete goes through when learning a new skill

    1- Unconscious Incompetence – The athlete is not thinking because they have never been told to think about anything, and are not very good at new skills. He said that he tells his athletes that it is better to look foolish in front of their teammates in practice and get better at the skills than to get embarrassed in front of an audience.

    2- Conscious Incompetence – The athlete is starting to understand the skill and try to execute it but are not very good at it yet.

    3- Concious Competence – The athlete has developed the skill but cannot perform it automatically and mindlessly. In this stage, unconcious action returns one to previous bad habits.

    4- Unconcious Competence – The skill has become automatic and performed perfectly with no concious effort. Attainment of this level takes not only practice, but mental imagery and rehearsal. It can take up to 500 of practice to achieve unconcious competence with a skill.   

    These are basic motor learning concepts….all proven by research (albiet using different terminology).
    [/quote]

    I should have quoted ut, cerbro, and flow from earlier in the discussion. : )

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    bear on #59450

    Barry welcome to the board. I'm glad you joined on here.

    Hi Mike! 

    The source of the force is irrelevant for the purpose of this discussion. I am speaking from a purely mechanical sense….the most basic and fundamental understanding of kinetics….and this is where you go woefully off course. To say that the direction of the force vector does not matter is absurd. If you are in fact arguing this issue (that direction of the force vector doesn't matter) please let me know and we'll discuss.

    I don't think I'm off course at all, let alone "woefully". Where did I say that the direction of the force vector does not matter? I think you may have gone off on a tangent, sort of a change in the vector of the discussion, so to speak.

    What in the world is 'chemical work' and how does this apply to the discussion of force vectors.

    Chemical work is the volitional contraction of the muscle by the athlete. An eccentric contraction does not require the brain to send a chemical signal to the muscle to contract. BTW this thread topic was about whether or not technique training is necessary, not about force vectors.

    (regarding length of ground contact time…br) No argument here. In fact, I argue that because ground contact time is so short one must PREPARE for it while still in flight in order to position the limbs in the most appropriate way to apply the largest possible forces in the appropriate directions.

    In the shot put analogy above, the thrower can make the adjustments to their throwing vector because they have the time to do so. The surface used on that day does not change between throws. It's a bad analogy, period. 
    But, preparing during flight time in the sprints? How does one "prepare" the limbs to be in the best position while traveling at speeds up to 26 mph? How does one think fast enough to send a signal for the muscles to react in hundredths of a second in order to line up a landing spot for the ultimate angle, adjusting for wind conditions and surface changes? How does one do this for stride after stride in rapid succession? I don't think so.

    No but they clearly can in 0.8-0.10s….the ground contact time for the best sprinters in the world.

    They clearly don't.  Force plates show force begins to register shortly after toe-down and peaks before the midpoint of the total stance time. That means you can cut almost 2/3 off the time you're using for an elite sprinter's ground contact time for force to begin registering, build to a peak and dissipate..This is where "technique" trainers are woefully off course because they neither understand the cause of this force nor its effects, relying solely on what they see. Force plates don't lie, they don't make up numbers, they don't sell books, they don't put on seminars with snappy quotes (yes, I do sell books and I do put on seminars but I'm not a force plate  :bigsmile:) and they ignore vectors. They merely register force. Despite all that, do you know anyone that can lift more than 3 times their bodyweight on one leg in .10 seconds? If you could find someone (you won't), could they do it over and over again for the number of strides in a 200m race? 100m? 50m?

    "When locomotion experts talk about the athlete's force application, the phrase generally used is " force to offset gravity". The runner applies isometric force to withstand hitting the ground without collapsing."
    Do you disagree with this point? I'm not clear by what you've said.

    First, it's not a matter of whether or not I agree with it, or whether or not you agree with it. It is what it is. It's a phrase used by locomotion experts to describe what happens at ground contact. How could I not agree with it? 

    I am in no way a 'sprint guru' and would argue that I have a fairly decent understanding of mechanics (USATF biomechanist for past 5 years; biomechanics PhD). Kinematics beget kinetics. This is a fundamental concept of biomechanics.

    Kinematics is defined as the branch of mechanics concerned with motion without reference to force or mass.
    Kinetics is defined as the branch of mechanics concerned with the forces that cause motions of bodies.

    The preponderance of sprint training protocols are based upon kinematics with little or no kinetic basis. From your background, you should know that force at ground contact comes from the runner as a falling and accelerating body and not as volitional chemical muscle mechanical work. 

    Please address the following questions:
    1. Does the direction of force applied to the ground matter at all?

    This is another "vector" question and an over simplification of the issue. Does it matter for the runner in the sense of volitionally creating a running vector? No. The combination of the runners isometric strength to offset gravity and the braking effect at toe-down create the runners vector. The vertical aspect dominates the horizontal, but both are necessary for forward propulsion.

    2. What is chemical work?

    Volitional contraction by the runner, with an excessive metabolic cost. The spring-mass model describes the method that minimises metabolic cost.

    3. Does the runner need to offset the effects of gravity?

    Yes, it is the most critical aspect. Mass-specific force to offset the effects of gravity has a linear relationship to speed. It is so critical that changing MSF by 1/10 the runners bodyweight could increase speed by 1 meter per second. It is not a "technique". MSF is primarily isometric.

    4. What is more important to sprinting- concentric strength or eccentric strength or some other form of strength?

    Concentric strength is critical at the start to overcome inertia and it is volitional. After the first few strides, pure concentric strength gives way to the spring-mass model's description of what is essenentially a bouncing ball using ground force reaction and eccentric loading that begins at ground contact. I have been diligent in looking, but so far, no one has come forward to take credit for the bouncing ball's training regime. Maybe they are too busy working on a new technique?

    5. How is "elastic force" produced?

    The short version: the overwhelming force at ground contact CAUSES the runner to dorsiflex the grounded foot, creating the eccentric contraction in the posterior muscles, tendons and ligaments. Potential elastic energy is produced and stored by the limb, then released as part of the vertical impulse. Elastic energy not used dissipates as heat.

    As for running mechanics, this is what the Weyand study states, "Although sprinting abilities differed greatly among subjects and the top speeds of the same runners differed considerably on the different inclines, the mechanical means by which runners increased speed from a jog to top speed varied little. Across each individual's speed range, speed increases were achieved primarily by increasing stride lengths at lower speeds and stride frequencies at higher ones. The more rapid increases in stride frequency as subjects approached their top speeds were achieved through reductions in both the contact and swing times that make up the total stride time…These aerial time reductions resulted from decreases in effective impulse, the product of contact time and effective force, which determines the time a runner spends in the air. Reductions in vertical impulse as top speed was approached were due to decreases in the time of foot-ground contact that were larger than the increases in the effective force applied to the ground."

    In a nut shell: There was little mechanical difference between a 11.1 mps runner and a 6.2 mps runner (no mention of significantly better technique causing significantly better running mechanics by the faster runners). Longer stride lengths early in the running gave way to increased stride frequency at higher speeds. Stride frequency increased because of reduced ground contact time and swing time (reduction in ground contact time because of better mechanics? No. Perhaps Newton's law? After all, it is the collision of 2 bodies, isn't it? ). Aerial times were reduced because because effective impulse (impulse in excess of mass) decreased (no mention of changes in running mechanics? better form? better angle of arms during armswings?). Effective impulse decreased because one of its factors, ground contact time, decreased. Top speed is the point where ground contact time has shortend to the point that no additional effective force can be applied to the ground.   

    No doubt this will tick off a lot of readers of this post, but none will be any more ticked off then I was for buying into a lot of unfounded, non-scientific nonsense.

    Barry Ross

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    bear on #59451

    The analogy is of "technique being of important" which is a cross of biomechanics and motor learning.  To me, it's not an analogy of they being similar movements.  I don't care how much force you cause to be applied to the ground, if the application of a force is wrong the system breaksdown.  In this case the system is a spring-mass system.  I have been stating for a while now if the angle of attack is wrong (essentially how far in front of the COM the foot touches down) that gct is increased regardless of speed (think inverted pendulum) and impulse is reduced with a reduction in stride length because of the dissipation of elastic energy that is not returned.   The problem of gct is not just related to leg stiffness and vertical stiffness.  As mike stated force is a vector, and if that vector is wrong, I don't care how stiff your body and legs are you will not have optimal mechanics.

    No disagreement with the above, in principle. The issue is cause and cure. Most believe it's a form defect that should be changed through technique training.
    The cause of the problem is where we differ, therefore so does the cure. If the athlete does not have sufficient strength to offset the effect of gravity, then elastic energy is dissipated and effective impulse is reduced. Aerial time is also reduced to the point where there is insufficient time to complete recycling and the runners foot will land forward of the COM. In severe cases, where there is a heel landing, metabolic cost increases and the runner tires more rapidly because the muscles are forced to work harder.
    Our cure? Increase strength to the point where the runner can apply more force to offset gravity, increase air time and bring the ground contact point closer to the COM. We've found that technique training is unnecessary to correct this problem. That being said, it doesn't mean that the runner will suddenly become the next Michael Johnson. 

    Barry Ross

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    Daniel Andrews on #59452

    [quote author="danimal9" date="1168911779"]
    The analogy is of "technique being of important" which is a cross of biomechanics and motor learning.  To me, it's not an analogy of they being similar movements.  I don't care how much force you cause to be applied to the ground, if the application of a force is wrong the system breaksdown.  In this case the system is a spring-mass system.  I have been stating for a while now if the angle of attack is wrong (essentially how far in front of the COM the foot touches down) that gct is increased regardless of speed (think inverted pendulum) and impulse is reduced with a reduction in stride length because of the dissipation of elastic energy that is not returned.  The problem of gct is not just related to leg stiffness and vertical stiffness.  As mike stated force is a vector, and if that vector is wrong, I don't care how stiff your body and legs are you will not have optimal mechanics.

    No disagreement with the above, in principle. The issue is cause and cure. Most believe it's a form defect that should be changed through technique training.
    The cause of the problem is where we differ, therefore so does the cure. If the athlete does not have sufficient strength to offset the effect of gravity, then elastic energy is dissipated and effective impulse is reduced. Aerial time is also reduced to the point where there is insufficient time to complete recycling and the runners foot will land forward of the COM. In severe cases, where there is a heel landing, metabolic cost increases and the runner tires more rapidly because the muscles are forced to work harder.
    Our cure? Increase strength to the point where the runner can apply more force to offset gravity, increase air time and bring the ground contact point closer to the COM. We've found that technique training is unnecessary to correct this problem. That being said, it doesn't mean that the runner will suddenly become the next Michael Johnson. 

    Barry Ross

    [/quote]

    Barry:

    I am not discounting the importance of resistance training and I know mike doesn't either, but I am not a sound board for him.  Strength helps hide flaws in technique, it should be secondary to learning, but it should be worked multilaterally.  Given 2 different 6-8 week periods over the past 2 years, one which worked primarily strength and the other which worked on accel development different athletes did each, but the end result has been the same in 55m race, but at the 200m distance there was a 1 s difference in improvement for the accel group.

    If you look at my "back to basics" thread, we did mostly general strength and dynamic flex work that provided the ability of body to have the active flexion and extension at the hip possible.  That's a specific application of strength to event performance.  While deadlifts and squats are great, they are a general application of strength to event performance.  In the spring mass system which we'll say predominates at the 40m mark for most.  The requirement is elastic strength, deadlifts and squats are still general applications, while the general strength is a specific application strength to ROM, but not force application, therefore in place hops and jumps, plus depth jumps, plus sprinting are more specific applications of force at gct.  Without the strength to actively flex and extend at the hip the athlete will not have the correct form.  You are right when you say our "cures" differ, and I agree that your cure will enhance performance, but is it not more logical to take a multilateral approach which cures both ends?

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    richard-703 on #59453

    I have heard about triple bodyweight "force" applied to the ground by sprinters (measurable by forceplates) and how no one could lift triple body weight, especially with one leg etc etc.
    This is misleading for a few reasons. It brings to mind a triple bodyweight one legged squat.

    1) Force is in units of mass times acceleration, not just mass, so there is no such thing as 450 pounds of force. I know that in common use this means the force that a mass exerts on say a floor due to gravity. So fine carry on.

    2) when a lifter lifts a weight, they must apply more force than just that of gravities force (or else the weight won't move).  In fact a fast bench presser for eg will be applying much more force than strictly would be necessary, if the weight were moved more slowly. So you don't need to lift triple body weight to apply that much force.

    3) The force plates measurement includes force due to the weight of the athlete.

    So if I stand on a force plate and very slowly deadlift my bodyweight, the plate will register slightly more than double bodyweight of "force" (the weight lifted plus my body weight). Fair is fair, include my bodyweight.

    If I lift it quickly, it will easily surpass triple body weight. Do the lift on one leg and presto, triple body weight off one leg. I could also do explosive one legged 1/4 squats with body weight on the bar for a similar result. All in all the force plate measurement isn't too surprising or amazing.

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    Daniel Andrews on #59454

    I have heard about triple bodyweight "force" applied to the ground by sprinters (measurable by forceplates) and how no one could lift triple body weight, especially with one leg etc etc.
    This is misleading for a few reasons. It brings to mind a triple bodyweight one legged squat.

    1) Force is in units of mass times acceleration, not just mass, so there is no such thing as 450 pounds of force. I know that in common use this means the force that a mass exerts on say a floor due to gravity. So fine carry on.

    Weight is a unit of force and thus pounds are not a unit of mass.  In the SI system the unit of force is typically a Newton (N), Mass is a Kilogram (kg), and acceleration is typically done as m/s^2.

    2) when a lifter lifts a weight, they must apply more force than just that of gravities force (or else the weight won't move).  In fact a fast bench presser for eg will be applying much more force than strictly would be necessary, if the weight were moved more slowly. So you don't need to lift triple body weight to apply that much force.

    actually yes, the force at the beginning is greater, but total work happens to be the same regardless of speed which means the distance to be traveled is a constant and thus total force is the same.  You can do this by plotting force on the Y axis and distance traveled on the X axis and measure the area under the curve or you could just integrate it.  This is also why medball throws, jump squats, jumps, bench throws, etc… are beneficial to the athletes training, they don't decelerate in the movement.

    3) The force plates measurement includes force due to the weight of the athlete.

    So if I stand on a force plate and very slowly deadlift my bodyweight, the plate will register slightly more than double bodyweight of "force" (the weight lifted plus my body weight). Fair is fair, include my bodyweight.

    If I lift it quickly, it will easily surpass triple body weight. Do the lift on one leg and presto, triple body weight off one leg. I could also do explosive one legged 1/4 squats with body weight on the bar for a similar result. All in all the force plate measurement isn't too surprising or amazing.

    ????  I think you are a little off here, the force plate measurement is because of ground contact when the athlete hits the force plate.  The measured result on the force plate is of mass (constant here), KE, PE, and elastic energy.  Therefore with the mass thrown out because we made this relative to mass it comes down to the speed of athlete, how high the vertical displacement of the athlete is, and how stiff their legs are.  This is also discounting the angular kinetics involved in the system, the speed of the foot at gc, etc…

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