Barry Ross on Ben and Maurice!

[system]

@lorien

Have you ever noticed how sprinting stays natural (‘thoughtless’ or ‘hind brain’ if you like) as long as you accelerate, and conversely; how numerous thoughts invade your head when deceleration takes over?

I agree and have though this for some time. I assume it is because you get kinesthetic feedback relating to you slowing down and “try” to find a solution to it conciously (obviously impossible and the opposite to what you want).

I am wondering now if once you hit a certain peak acceleration distance (say 50-60m) relaxation becomes easier because you have less sensation of slowing down?

Relating to KK’s thoughts on John Smith never wanting his athletes to reach absolute maximum speeds, this makes sense because I feel that your body can tell when it is no longer capable of accelerating and this feedback switches you out of the unconcious running action and into concious analysis mode - which makes relaxation and automation more difficult. Many times in the past my PB races were the ones where i almost stopped trying - perhaps it was the tryptophan but i almost felt sleepy. Fast but no fully aware.

Back on track: whether or not WannaGetFast’s idea is junk science or not - it has created some great debate and I have learned a lot. However, I am loosing track of the points being originally argued… anyone like to summarise?

[Charlie_Francis]

The comment about thought entering your head when deceleration takes over should be reversed! When thoughts enter your head, everything gets buggered up and you slow down.

[system]

Charlie,

What are your strategies to avoid “thoughts entereing the head”? Does this all come under your idea of “waiting for it”?

TC

[alexmicha]

@tc0710

I agree and have though this for some time. I assume it is because you get kinesthetic feedback relating to you slowing down and “try” to find a solution to it conciously (obviously impossible and the opposite to what you want).

I am wondering now if once you hit a certain peak acceleration distance (say 50-60m) relaxation becomes easier because you have less sensation of slowing down?

Relating to KK’s thoughts on John Smith never wanting his athletes to reach absolute maximum speeds, this makes sense because I feel that your body can tell when it is no longer capable of accelerating and this feedback switches you out of the unconcious running action and into concious analysis mode - which makes relaxation and automation more difficult. Many times in the past my PB races were the ones where i almost stopped trying - perhaps it was the tryptophan but i almost felt sleepy. Fast but no fully aware.

Back on track: whether or not WannaGetFast’s idea is junk science or not - it has created some great debate and I have learned a lot. However, I am loosing track of the points being originally argued… anyone like to summarise?

Yes. I will take a shot at summarization.

But first, in response to Lorien immediately above your quote, 4 studies are listed that demonstrate increasing horizontal GRFs with increasing sprinting velocity (Payne, Fukunaga, Tsujino and Kyrolainen) [as seen in the 2nd quote of this forum, page 23, under alexmicha].

In summary,

1. vertical GRFs are greater than H GRFs in a sprint, But…

2. H GRFs are @ 1/3rd V GRFs at peak velocity, thus they are significant and cannot be ignored

3. H GRFs become increasingly more important as velocity is increased from a slow run to a sprint

4. H power output is greater than V power output at peak velocity in a sprint

5. Because H GRFs and H power are significant in peak velocity, the sprint athlete should place some focus on the H muscles (hip m.) in training

6. The statement that momentum alone carries the athlete through peak velocity (terminal velocity) without any horizontal propulsion is inaccurate for a maximal sprint, but is valid for submaximal constant velocity running.

[pierrejean]

The problem is that all the parameters of kinematic and dynamic of running don’t all raise at the same rate with the raise of sprinting speed, and the litterature reports data for speeds up to 11m/s only (Mann, Mero/komi, Alexander, Natta/Rega, etc). The fastest sprinters are able to reach 12m/s and we don’t know the parameters numbers for these intensities. Also, the studies doesn’t use a large enough number of runners for the experimentations to make statistics. Add all the findings of the various studies is not possible due to different conditions during the experimentations.

[Bear]

I would like to express here that the Harvard/ Weyand study is incorrect in its conclusion regarding rate of leg movement. That study demonstrates that the time spent in swing phase is equal for fast (F) and slow (S) runners. The study states that, because the TIME spent repositioning the legs is equal between F and S runners, the conclusion is that the RATE of leg movement is no different between F and S runners. The error is that one cannot convert data on time to data on rate of movement.

Let’s make sure we all understand what the study said: “The swing times of the 33 runners who completed the level protocol did not vary significantly in relation to their top running speeds.” It further states that, “both fast and slow runners required an aerial time of 0.128 s to achieve the minimum swing
time required to reposition their legs for the next step.” We should add this also, “faster human runners take considerably longer strides” and “Certainly, top sprinters have faster muscle fibers and greater muscular power available to reposition their limbs yet do so little or no faster than average and slow human runners do.”
No where does it state a conclusion that, “the RATE of leg movement is no different between F and S runners.” If you’re trying to make a point don’t do it by misrepresentation. The last quote addresses your “error”. It clearly implies that faster runners could repostiton their legs faster but they don’t. They don’t because longer stride lengths make it unnecessary to move their legs faster.

We should also keep in mind that there are numerous studies that cite the Weyand study. Obviously experts in locomotion don’t see the pitfalls or “errors” you suggest.

Swing time (as I am using it here) refers to double-legged swing phase. Double-legged swing phase time is really air phase time.
AIR PHASE TIME IS DEPENDENT SOLELY ON VERTICAL DISPLACEMENT AND HAS NO BEARING ON FORWARD MOVEMENT OF AN OBJECT, OR ATHELTE.
Another manner of looking at this statement is that, when one describes forward speed and tries to relate that to air phase time then it is wrong.
This fact is based on simple physics. For example, if you throw an object up and wait for it to come down, then the amount of time in the air (ie., air phase time) is dependent only on vertical displacement (which is the distance that it goes up and down). Nothing else determines air phase other than vertical displacement. We can carry out this example further to clarify my point even more.
Let’s say that you have two balls. Let’s then say that you throw one ball up and down and a little distance forward, and that it moves exactly 1 meter in vertical distance and it moves forward 1 meter. Then you throw the second ball 10 meters forward and you do it in a way that its vertical displacement during that throw is exactly 1 meter. With this scenario both balls have equal vertical displacements, 1 meter. Because they both have equal vertical displacements it will take equal amount of time (ie., equal air phase time) for them to go up and down. But this tells you nothing of forward movement. The 1st ball moves 1 meter in x time, whereas the 2nd ball moves 10 meters in x time. The second ball has greater horizontal speed because it moves 10 meters in x period of time, whereas ball one only moved 1 meter in x period of time. Greater horizontal speed for ball 2 means that its COM has greater speed than ball 1 even though both balls have equal air phase times (equal vertical displacements). This is analogous to S and F sprinters. S and F sprinters have equal vertical displacements, but the F sprinters have greater SL (ie., SL in air phase], which means that they have greater horizontal movement. Because F runners horizontal movement is greater and it occurs in an equal time period it means that rate of movement COM is greater for F sprinters…

Nice try, but no cigar. Just exactly where does it say that horizontal movement occurs in an equal time in the Weyand study? Where does it say they have equal vertical displacements? It says that it takes a MINIMUM aerial time of 0.128 to achieve the MINIMUM swing time to reposition their legs in the air. Does that read “equal” times to you? It sure doesn’t to me. Did you make an ERROR?

Because movement of the COM is dependent on, and determined by leg movement, one can conclude that the rate of leg movement is also greater for F sprinters during Swing phase, or air phase (and Stance phase as was discussed above)

This is simply poor logic. One does not follow from the other. Leg movement is not the mover of COM, it is the work produced by the leg movement against the ground that causes COM to move. In essence what you’re saying is this: If I jump in the air and swing my legs as fast as I can, I will move horizontally at a higher/medium/lower rate of (you pick it) speed. According to your theory, If I drive a car up a ramp at 40 miles per hour, launch off the end and land 100 feet away, while you drive at 50 miles per hour on the same ramp and land 130 feet away, and both of our tires continued to rotate while we were airborne, your tires must have been rotating faster than mine in the air because automobile movement is dependent on tires so that’s what gave you the extra distance. Is this a ludicrous example? No more so than yours.

And you think Weyand is flawed? If a runner has sufficient time, more than the mimimum amount of time to reposition their legs before landing, and they only need to be in the proper position for landing, then why would they try to reposition them faster (which means moving the limbs faster to get them into postion faster, same as what Weyand meant)? If moving your legs in the air as rapidly as you can moves you forward, why not just do that and not touch down at all? Your premise and conclusions are severely flawed.

I do not have the 1987 biomechanics article, but I have read something along the lines that vertical GRF (ground reactive force) is 10 times greater then the horizontal force. But this is based on constant running at a relatively slow pace. I have seen a (? Japanese study, I will have to find the reference) which demonstrates that horizontal GRFs are roughly 1/3rd those of vertical GRF. Even though a 1/3rd GRF is small it is still significant and needs to be dealt with if one wants to maximiza sprint speed. What this means is that one cannot ignore the horizontal GRFs - simply focusing on verticla GRFs will not allow maximization of sprinting speed.

The 1987 study: Munro C, Miller DI, and Fuglevand AI. Ground reaction forces in running: a reexamination. J Biomech 20: 147–155,1987.

For the second study, perhaps your thinking of the study that compared the metabolic cost of the horizontal portion of running, concluding that is was 1/3 of the total metabolic cost of running at top speeds: Young-Hui Chang and Rodger Kram , Metabolic cost of generating horizontal forces during human running
J Appl Physiol 86: 1657-1662, 1999; 8750-7587/99 , and perhaps you’re not.

I’m not sure why you brought up either study, since vertical GRF is the ground reaction force (Newtons 3rd) caused by gravity forcing the runner back to the ground. How does that relate to your initial premise? Since GRF is ground reaction force there is no GRF unless you actually touch the ground. How do you create horizontal GRF in the air?

And since “When one runs at a constant speed against no air resistance, the propulsive forces that increase the body’s forward velocity before takeoff simply offset the braking forces that decrease the body’s velocity on landing. In the present experiment, both the net horizontal forces exerted to propel the body forward and the effect of these forces on forward speed must be zero regardless of the top speed attained by the runner” how much time do you need to spend on horizontal force development (other than the start, which you weren’t addressing.)

I would like to finish by repeating that the Harvard study came about an erroneous conclusion. In other words, LEG REPOSITIOINING RATES are important. The rate of hip rotation is an important factor that determines sprinting speed.

I am repeating this not to sound gallant or denounce the study or the authors. The study brings out many important points. However, when sprint coaches are told that the rate of leg movement, or the rate of hip rotation is unimportant then it is a disservice not to set the record straight.

It’s not Weyand who’s putting out erroneous information, you are.

Barry Ross

[Bear]

@pierrejean

The problem is that all the parameters of kinematic and dynamic of running don’t all raise at the same rate with the raise of sprinting speed, and the litterature reports data for speeds up to 11m/s only (Mann, Mero/komi, Alexander, Natta/Rega, etc). The fastest sprinters are able to reach 12m/s and we don’t know the parameters numbers for these intensities. Also, the studies doesn’t use a large enough number of runners for the experimentations to make statistics. Add all the findings of the various studies is not possible due to different conditions during the experimentations.

What then are you using to train by? What did you base your methodology on if there is insufficient information available?
What proof do you have, from a scientific standpoint that there is enough difference between an 11.1m/s and a 12m/s that anything needs to be done differently? You don’t use any current studies by locomotion experts so what exactly do you go by? Stuff from 1950?
Treadmills are used indoors to remove as many variables as possible (and when tested against runway force plates there is minimal differences if any) but you don’t like them and then you say that there are too many variables. What do you use to justify how you coach? Do you simply guess and hope for the best?

[Bear]

@alexmicha

We need to get one thing straignt concerning horizontal forces. The studies tha Weyand refer to use relatively slow running speed. The most common is Munro, (GRF in running: a re-examintation, J Biomech, 20: 147-55, 1987). Running speeds in that study were 2.5-5.5 m/s, a fast jog or run.

Several other studies (read on) demonstrate much more significant GRFs in the horizontal plane when speeds are increased to sprinting, ie., more thant 8 m/s.

Payne (Ergonomics, 11(2), 123-434, 1968) demonstrates peak vertical (V) forces at 600N and peak H forces at 200N at speeds @ 8 m/s. A 1/3rd ratio, which is much more significant than the 1/10th difference for slow runs.

Fukunaga ((Ergonomics, 24(10): 765-772, 1981) demonstrates max H propulsive force of 200-300N at max speeds 6-8 m/s. Max V forces are 600-900N. Again a 1/3 ratio.

Tsujino (Kobe J Med Sci, 12:1-26, Jan, 1966) demonstrates that max H propulsive force is 36% that of max V force (pretty much the same 1/3rd ratio as the above studies) at speeds of 9.5 m/s (ie., 10.5 sec for 100m).

Further analysis of Tsujino’s data demonstrates that the rate of development of force is greater for H component than for the V component. Rate of development of force is power, thus horizontal power is greater than V power at max sprinting speeds.

Fukunaga also shows that acceleration for each swing leg is 4 m/ss at peak velocity. Thus, with constant running velocity there is still the need for acceleration (or propulsion) of the leg to go forward. This is corroborated by EMG studies that demonstrate large hip flexor muscle activity in early to mid swing phase.

Kyrolainen (Med Sci Sports Exerc, 33(8): 1330-1337, 2001) demonstrates peak V forces at 2134N and peak H forces at 675N at a velocity of 6.5 m/s. This 1/3rd ratio is consistent with the above studies.

Kyrolainen, in addition, demonstrates that when speed is increased from 3 to 6.5 m/s the H forces increases 187%, whereas the V forces increase by only 28%. If you extrapolate this to 9.5 m/s then it shows the ever increasing H forces with increasing running speed.

Conclusion:

1. Horizontal forces are significant at peak velocity, thus cannot be ignored in training.
2. Horizontal muscle power is greater at peak velocity than vertical muscle power.
3. You CANNOT QUOTE studies using slow running speeds to come up with the conclusion that Horizontal GRFs are not significant during peak velocity of a sprint.

How about blessing us with more information so we can examine studies from 1966, '68, and '81.

Your extrapolation from Karolainen is ridiculous, since you would expect more horizontal force early in the race to overcome inertia and less at top speeds.

How does this “max H 200-300N at max speeds 6-8 m/s. Max V forces are 600-900N” in 1981 become “peak V forces at 2134N and peak H forces at 675N at a velocity of 6.5 m/s” in 2001"?

[pierrejean]

@Bear

What then are you using to train by? What did you base your methodology on if there is insufficient information available?
What proof do you have, from a scientific standpoint that there is enough difference between an 11.1m/s and a 12m/s that anything needs to be done differently? You don’t use any current studies by locomotion experts so what exactly do you go by? Stuff from 1950?
Treadmills are used indoors to remove as many variables as possible (and when tested against runway force plates there is minimal differences if any) but you don’t like them and then you say that there are too many variables. What do you use to justify how you coach? Do you simply guess and hope for the best?

What proof do you have, from a scientific standpoint that there is enough difference between an 11.1m/s and a 12m/s that anything needs to be done the same?

In all these bibliographies how many used spikes. I don’t need a scientific article to claim that running in flats and running in spikes change the parameters, mechanically and psychologically for the runner.

My methology is based on the work done by Ionov, Hess, Susanka, Levchenko, Bruggemann among others who analysed basic biomechanical parameters during international competitions and not treadmill or laboratory.

As for training season planning i use adaptations of sprint Bulgarian methods as decribed by Antonov and Dimitrov and GDR method as described by Tepper, Hess and Eber. And Charlie Francis of course, among others. What he says is more usefull than any scientific studies published because he was on the real world of competition. Please tell me a single scientific study which help to periodise season for elite sprinters. What i mentioned was based on coaches who had mistakes and success and who built from practical experience efficient programs, not scientific programs i don’t believe in that.

For the choice of distances during training you have a résumé of my method + explanations here http://www.charliefrancis.com/community/showthread.php?t=11572
You see that i still use science…

If it’s scientific things, i hope the findings of 1950 are still true. If not, the one done in 2005 will turn out to be false some decades later and i’m not interested on it.
I prefer use pragmatic approach and listen to experienced coaches. Each athlete is a new story and i’m afraid science won’t help.

[lorien]

There is a difference in applying scientific principles in a test and doing authentic science. From a strictly scientific standpoint, the validity in any treadmill research is highly questionable, if they are used to explain top level sprinting without a treadmill (simple as that) – I bet science theorists would find it really hard to even call it science. We need really strict scientific studies that evaluate all the differences between treadmill studies and studies done with real running before we go about explaining anything else. And still, we’re in trouble when we apply laboratory results to real life situations. Athletics is not mathematics, the term “bio” attached to -physics, -chemistry and –mechanics is always going to make absolute scientific claims questionable (the variables, known and unknown, are too many).

[Bear]

@pierrejean

What proof do you have, from a scientific standpoint that there is enough difference between an 11.1m/s and a 12m/s that anything needs to be done the same?

In all these bibliographies how many used spikes. I don’t need a scientific article to claim that running in flats and running in spikes change the parameters, mechanically and psychologically for the runner.

My methology is based on the work done by Ionov, Hess, Susanka, Levchenko, Bruggemann among others who analysed basic biomechanical parameters during international competitions and not treadmill or laboratory.

As for training season planning i use adaptations of sprint Bulgarian methods as decribed by Antonov and Dimitrov and GDR method as described by Tepper, Hess and Eber. And Charlie Francis of course, among others. What he says is more usefull than any scientific studies published because he was on the real world of competition. Please tell me a single scientific study which help to periodise season for elite sprinters. What i mentioned was based on coaches who had mistakes and success and who built from practical experience efficient programs, not scientific programs i don’t believe in that.

For the choice of distances during training you have a résumé of my method + explanations here http://www.charliefrancis.com/community/showthread.php?t=11572
You see that i still use science…

If it’s scientific things, i hope the findings of 1950 are still true. If not, the one done in 2005 will turn out to be false some decades later and i’m not interested on it.
I prefer use pragmatic approach and listen to experienced coaches. Each athlete is a new story and i’m afraid science won’t help.

I read your methods on the thread you gave. It appears that your method is to take one sprinter, like Greene, who is as unique as any other sprinter in form and style, and try to match other sprinters that you coach to that standard. Some way or other. At the same time you post on this thread that scientists don’t use a large enough number of runners for the experiments, yet you based training parameters on exactly one, or at least that’s the impression from reading the thread you gave.
You mention several others who you rely on whose analysis was based purely on anecdotal information under varying conditions on different surfaces because treadmills under controlled conditions aren’t accurate.
You don’t use science, you guess.

I’m surprised you mentioned cns since you have no measurements of the effects of cns during running. Those effects aren’t visual, so you wouldn’t be able to measure them, let alone know what they are, unless you guess.

Your answer to the question regarding the differences between running at 11.1m/s and 12m/s was the difference between running in flats and running in spikes. I’m not sure how that works…

It is certainly not logical to assume that any test done in 1950 or the '60s, or any other time period, that may be found to be inaccurate would mean that tests done today will be inaccurate tomorrow or any other time.

Scientific tests aren’t meant to discover how to use the information in training, only to provide information on what occurs during the testing. It’s up to the coach to decipher the information and decide both the usefulness and method of adaptation to each athlete. You’ve made it clear that you find no use for the information at all.

[pierrejean]

Bear,

I don’t know why you attack my methods while you don’t know it. In the other thread, i gave Maurice Greene as example (an extreme example who is able to accelerate up to 60m while my fastest athlete is able to accelerate up to 50m). I have similar data for each of my athletes, so i work on individual data, not Maurice’s, it would be stupid to do so.

Effects on CNS or other things can be seen on the athlete’s times, behaviour and other visual test i have. The way athlete shake my hands at first contact of the day is for me the first indicator of what can be done on a given day. Is psychology a science?

I didn’t say the difference between 11.1m/s and 12m/sec is running with spikes, i know my english sucks at times, but… the 11.1m/sec may refer to the downhill treadmill with flat running shoes i suppose, while 12m/sec was done in competition on track with spikes. Apple and orange.

You may claim Weyand as a scientific base to promote your method, but i don’t see the link.

[Bear]

@lorien

There is a difference in applying scientific principles in a test and doing authentic science. From a strictly scientific standpoint, the validity in any treadmill research is highly questionable, if they are used to explain top level sprinting without a treadmill (simple as that) – I bet science theorists would find it really hard to even call it science. We need really strict scientific studies that evaluate all the differences between treadmill studies and studies done with real running before we go about explaining anything else. And still, we’re in trouble when we apply laboratory results to real life situations. Athletics is not mathematics, the term “bio” attached to -physics, -chemistry and –mechanics is always going to make absolute scientific claims questionable (the variables, known and unknown, are too many).

There are studies done on treadmills to test their accuracy against over ground running. And we apply laboratory results to real life situations all the time. No legitimate scientist will claim their findings are absolute, they don’t use the “p” word…prove. The will conclude or deny.

What I’m suggesting is that the methodology presented by many (not all, certainly) posters on this, and other sites, is more often than not based on visuals and experiences derived from groups of singular instances of ancedotal evidence. This misinformation is then used to prove a point. These instances are under differing conditions of weather, track surfaces, equipment, and athletic psyche, with minimal reference points for accurate measurments, no analysis of forces, no analysis of metabolic costs, and on and on ad infinitum.
Yet when the dirty word “science” is whispered, the hounds unleash themselves.

[Bear]

@pierrejean

Bear,

I don’t know why you attack my methods while you don’t know it. In the other thread, i gave Maurice Greene as example (an extreme example who is able to accelerate up to 60m while my fastest athlete is able to accelerate up to 50m). I have similar data for each of my athletes, so i work on individual data, not Maurice’s, it would be stupid to do so.

Effects on CNS or other things can be seen on the athlete’s times, behaviour and other visual test i have. The way athlete shake my hands at first contact of the day is for me the first indicator of what can be done on a given day. Is psychology a science?

I didn’t say the difference between 11.1m/s and 12m/sec is running with spikes, i know my english sucks at times, but… the 11.1m/sec may refer to the downhill treadmill with flat running shoes i suppose, while 12m/sec was done in competition on track with spikes. Apple and orange.

You may claim Weyand as a scientific base to promote your method, but i don’t see the link.

No, you didn’t answer the 11.1m/s to 12m/s at all and it had nothing to do with a downhill treadmill
I’m a strength coach, and my method is not affected by the Weyand study at all. Weyand does offer a scientific base, do those who preceed is study and those who cite his study. The rest are anecdotal and guessing, or the voodoo of shaking hands.

[pierrejean]

I odn’t understand what you mean with the 11.1 and 12m/sec nor i understand what you want me to answer?

About Weyand, you mention his study in the introduction of you book. If you method is not affected by it at all, why bother to mention it?

There’s no voodoo in shaking the ahlete’s hands, that’s just usual human beeings relationships. It may not be part of laboratory testing procedure, but that’s the everyday life in training stadiums and my first impression of the athlete in the given day. I realise that “impression” may refer to something irrational and not scientific at all, sorry… i’m just human.

[Charlie_Francis]

@Bear

No, you didn’t answer the 11.1m/s to 12m/s at all and it had nothing to do with a downhill treadmill
I’m a strength coach, and my method is not affected by the Weyand study at all. Weyand does offer a scientific base, do those who preceed is study and those who cite his study. The rest are anecdotal and guessing, or the voodoo of shaking hands.

In “Speed Trap” you can read references to the vertical action of top sprinting, written in 1989, based on experience, both coaching and sprinting, going back to the late 1960s, and instruction I received based on experiences from the 40s and 50s. Weyand is not breaking new ground with that portion of his research, nor does truth become stale-dated.
What you interpret as “vodoo”, I would call the art of coaching. I’m pretty sure you invoke similar instincts, developed from experience, in the weight room to decide when your own athletes have had enough.

[Bear]

@pierrejean

I odn’t understand what you mean with the 11.1 and 12m/sec nor i understand what you want me to answer?

About Weyand, you mention his study in the introduction of you book. If you method is not affected by it at all, why bother to mention it?

There’s no voodoo in shaking the ahlete’s hands, that’s just usual human beeings relationships. It may not be part of laboratory testing procedure, but that’s the everyday life in training stadiums and my first impression of the athlete in the given day. I realise that “impression” may refer to something irrational and not scientific at all, sorry… i’m just human.

This is what you said regarding studies, “and the litterature reports data for speeds up to 11m/s only (Mann, Mero/komi, Alexander, Natta/Rega, etc). The fastest sprinters are able to reach 12m/s and we don’t know the parameters numbers for these intensities.”

I’m asking you why you made that statement. What makes you think having information up to 12m/s would change the results? How does your not knowing the parameter numbers of these intensities make you disbelieve the results of the study, or feel uncomfortable about applying it to elite athletes?

[Bear]

@Charlie_Francis

In “Speed Trap” you can read references to the vertical action of top sprinting, written in 1989, based on experience, both coaching and sprinting, going back to the late 1960s, and instruction I received based on experiences from the 40s and 50s. Weyand is not breaking new ground with that portion of his research, nor does truth become stale-dated.
What you interpret as “vodoo”, I would call the art of coaching. I’m pretty sure you invoke similar instincts, developed from experience, in the weight room to decide when your own athletes have had enough.

I agree that there is no groundbreaking in regards to vertical action. What is different in Weyand is how you get there, whether its gravity and elastic energy or muscle mechanical energy. There is a significant difference between them in regards to coaching protocols.

I do use some “voodoo” tactics myself at times.

[Wannagetfast]

To answer the t-mill question.(I know this group hates t-mills and that’s fine, but for what we are talking about it fits.)
tmill vs. track: In the 2003 paper (Bundle, Hoyt, Weyand, Journal of Applied Physiology. 2003 Nov; 95(5):1955-62. Some explanation that might help with the T-mill VS over ground confusion.

About wind resistance. Charlie in your sprint heyday many moons ago, did you feel any difference in mechanics when you ran your fastest legal wind times? In other words, as we sprint faster, and wind resistance is greater, the suggestion is that we need to increase horizontal propulsive forces to overcome this. Right?

In my experience and many others I would believe, sprinting in the absence of any appreciable wind, I’ve never felt that I’ve changed anything mechanically once I was up to speed. That would assume that I could somehow make some sort of correction to reduce resistance. Sounds weird huh? This would certainly work when we know we are experiencing a strong headwind and in leaning forward may create less drag, but I’m curious if elite athletes, for speed induced wind increases; consciously change a mechanic at very high end speeds just because they intuitively feel that, as they are going faster, they will be experiencing greater resistance?

To me, they just sprint, and at the end of the race let the anemometer reading give them an idea of why they ran faster or slower with the help of wind or not?

[alexmicha]

@Bear

Let’s make sure we all understand what the study said: “The swing times of the 33 runners who completed the level protocol did not vary significantly in relation to their top running speeds.” It further states that, “both fast and slow runners required an aerial time of 0.128 s to achieve the minimum swing
time required to reposition their legs for the next step.” We should add this also, “faster human runners take considerably longer strides” and “Certainly, top sprinters have faster muscle fibers and greater muscular power available to reposition their limbs yet do so little or no faster than average and slow human runners do.”
No where does it state a conclusion that, “the RATE of leg movement is no different between F and S runners.” If you’re trying to make a point don’t do it by misrepresentation. The last quote addresses your “error”. It clearly implies that faster runners could repostiton their legs faster but they don’t. They don’t because longer stride lengths make it unnecessary to move their legs faster.

We should also keep in mind that there are numerous studies that cite the Weyand study. Obviously experts in locomotion don’t see the pitfalls or “errors” you suggest.

Nice try, but no cigar. Just exactly where does it say that horizontal movement occurs in an equal time in the Weyand study? Where does it say they have equal vertical displacements? It says that it takes a MINIMUM aerial time of 0.128 to achieve the MINIMUM swing time to reposition their legs in the air. Does that read “equal” times to you? It sure doesn’t to me. Did you make an ERROR?

This is simply poor logic. One does not follow from the other. Leg movement is not the mover of COM, it is the work produced by the leg movement against the ground that causes COM to move. In essence what you’re saying is this: If I jump in the air and swing my legs as fast as I can, I will move horizontally at a higher/medium/lower rate of (you pick it) speed. According to your theory, If I drive a car up a ramp at 40 miles per hour, launch off the end and land 100 feet away, while you drive at 50 miles per hour on the same ramp and land 130 feet away, and both of our tires continued to rotate while we were airborne, your tires must have been rotating faster than mine in the air because automobile movement is dependent on tires so that’s what gave you the extra distance. Is this a ludicrous example? No more so than yours.

And you think Weyand is flawed? If a runner has sufficient time, more than the mimimum amount of time to reposition their legs before landing, and they only need to be in the proper position for landing, then why would they try to reposition them faster (which means moving the limbs faster to get them into postion faster, same as what Weyand meant)? If moving your legs in the air as rapidly as you can moves you forward, why not just do that and not touch down at all? Your premise and conclusions are severely flawed.

The 1987 study: Munro C, Miller DI, and Fuglevand AI. Ground reaction forces in running: a reexamination. J Biomech 20: 147–155,1987.

For the second study, perhaps your thinking of the study that compared the metabolic cost of the horizontal portion of running, concluding that is was 1/3 of the total metabolic cost of running at top speeds: Young-Hui Chang and Rodger Kram , Metabolic cost of generating horizontal forces during human running
J Appl Physiol 86: 1657-1662, 1999; 8750-7587/99 , and perhaps you’re not.

I’m not sure why you brought up either study, since vertical GRF is the ground reaction force (Newtons 3rd) caused by gravity forcing the runner back to the ground. How does that relate to your initial premise? Since GRF is ground reaction force there is no GRF unless you actually touch the ground. How do you create horizontal GRF in the air?

And since “When one runs at a constant speed against no air resistance, the propulsive forces that increase the body’s forward velocity before takeoff simply offset the braking forces that decrease the body’s velocity on landing. In the present experiment, both the net horizontal forces exerted to propel the body forward and the effect of these forces on forward speed must be zero regardless of the top speed attained by the runner” how much time do you need to spend on horizontal force development (other than the start, which you weren’t addressing.)

It’s not Weyand who’s putting out erroneous information, you are.

Barry Ross

I did make an error in my explanation. (Maybe it in the wording.) I apologize for the misunderstanding. I do not want to give the wrong information. Could I try to re-explain this matter?

Peter Weyand concludes that more rapid leg movements in swing phase do not determine a faster running speed. I agree with the fact that maximal rate of leg movement does not matter. This is because the degree of maximal hip flexion varies amongst athletes.

Next, I interpret that ‘more rapid leg movement’ means ‘rate’ doesn’t it. I mean if an object moves ‘rapidly’ we are talking about the rate (ie., How fast is it going? “rapidly”) that the object moves, aren’t we?

But the leg moves a greater distance (greater SL swing) in an equal time (equal air phase time of 0.l28). THis means that the AVERAGE rate of leg movement has to be greater. In other words, for F runners they reposition their legs (meaning repositioning the leg from one toe-touch to the next toe-touch) a greater distance (greater SL) in an equal period of time (0.0128 s).

So the ratio SL/ time is greater, which is really the rate of movement. This is average rate of leg movement. (That is my point on rate.)

Such greater average leg movement is generated during contra-lateral stance phase, and not during double-legged swing (air) phase, as you mention.

I understand that the studies I quote are ‘old’. But it rather remarkable that the ratio of Horizontal (H) to V forces at peak velocity is @ 1/3rd for all of these studies. The point is that GRFs are increased in both the V and H plane at peak velocity.

Total Forces (GRFs) are increased with greater running velocity. (WE all agree on that one.) They are increased because the same impulse that is created by F and S runners is generated in a shorter ground contact time (GCT) for F runners. For the F runner to be able to generate an equal impulse as a S runner, but to do so in a shorter time period requires that a greater force is applied.

The GRFs are greater in the horizontal plane because the impulse is generated in a much shorter time period than during acceleration phase. SO, yes, horizontal forces are greater in peak velocity than they are in acceleration phase of a sprint. (I believe that you are in disagreement with this statement)

As far as vertical displacement. It is dependent on air phase time, so if air phase times are equal between F and S runners then vertical displacements are also equal.

Leg movement
I am trying to say that leg movement is a result of vertical and horizontal forces at peak velocity. Based on the above evidence the H/V forces are roughly 1/3. If you disagree because the above studies are old then I am wrong. But, again they are remarkably consistent.

Final point to all of this is, my summary:

The horizontal forces are a necessary component component at peak velocity, even though vertical forces are the more important ones. (If you disagree then you interpret this as erroneous information, but you may ignore it.)

I am not trying to spread erroneous information and again I apologize for any mis-interpretations.

For those who believe in horizontal propulsion forces at peak velocity there is ample evidence supporting such a concept.

As far as Weyand study I apologize for my error in interpretation.

Weyand study confirms a longer SL for F runners that occurs in an equal air phase time. I am merely trying to say that the longer SL (which is a horizontal component) is increased because of horizontal propulsion forces that are generated by those muscles responsible for that increased SL (ie., hip flexors and extensors)

For those who disagree then you may simply ignore such information.