I am happy I am not the only one that questions the use of box jumps, especially with landing positions. When looking for photos of google I stumbled on this blog, and it’s refreshing that other people understand that landings are a vital component of jumping. Box jumps are favored by some as they seem to improve quickly, but actual displacement and shoving your feet to your throat is not the sam
Box Jumps: The Good, The Bad, The Ugly
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Let me be another one who questions the use of box jumps. I believe they are of limited value since the athlete does not concentrate on leg and ankle extension which is most important to a runner and jumper. I’m a firm believer that they will ingrain bad habits if box jumps are used extensively. This is why I omitted box jumps in my books Explosive Running and Explosive Plyometrics. The athlete can gain much more by doing other types of plyometric exercises rather than relying on box jumps that do not duplicate any of the movements seen in running or jumping.
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You both would still advocate depth jumps and drop jumps though, yes?
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Jumping off from a box to another or just off of it is advanced…..most athlete can’t handle that and some have won medals without it. The main thing is purposeful programming. History of good training programs show little impact of the plyos with sprinting but jumps is a different story.
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Alex, yes I would advocate depth jumps. They are very important in plyometric training. Please define what you mean by drop jumps. I have seen several definitions of this. Carl, is this what you mean by just jumping off a box? is it a drop down with a hold in the bottom position? The term for this is usually altitude jump
I believe that plyos have a major impact in a good training program especially for sprinters. Jump training appears to be the best for long-distance runners. This appears to be substantiated by specificity of training. Can you explain how you came to your conclusions?
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What about box jumps up to teach the mechanics of jumping while reducing the eccentric stress upon landing?
I think shoving your feet to your throat is youtube sensationalism and not, as Carl puts it, practical programming.
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NFL combines.
Verters Vs 40’s. Pattern emerges.
Original Link: https://www.nfl.com/combine/top-performers#workout=FORTY_YARD_DASH&year=2011&position=QB-RB-WR-TE-S-DL-LB-CB-OL-SPEC
Original Link: https://www.nfl.com/combine/top-performers#workout=VERTICAL_JUMP&year=2011&position=QB-RB-WR-TE-S-DL-LB-CB-OL-SPEC
Also still no love for the thread: [i]Vibration REDUCES plantar flexion FORCE due to prolonged tendon vibration[/i].
Playing with the devil?.
Some good data points but bad verticals are not indicators of good speed. Also CMJ vs SJ would be nice to see with NFL athletes….on a force platform as well as vertec.
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The question is why use boxes anyway, since jumping of a box is just coming down from a specific height? Jumping on a box has use…but you can work on landing mechanics with smaller amplitude jumps. Most boxes are overpriced, and some like the pyramid boxes stink because they teach a narrow landing stance.
CV
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Some good data points but bad verticals are not indicators of good speed. Also CMJ vs SJ would be nice to see with NFL athletes….on a force platform as well as vertec.
The question is, why is that?.
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Ato, Donovan, and Linford….Golden Boys.
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Going by the NFL combines, good verticals are not indicators of good speed neither. The question is, why is that?.
In terms of jumping onto boxes. I might take that up when… well… when I want to get good at jumping onto boxes.
Have you seen these guys that can jump over cars & who knows what else?.
Can’t move for toffee.
World-class verticals do not imply world-class speed and vice-versa, however they are certainly correlated. I’m sure that every elite sprinter has a 30-40″+ vert.
40yd times are not the best measure of speed, but acceleration, where strength and power is more important than elasticity. These guys who jump who jump 35″+ at the combine I’m sure can run low/mid-10 100m, or at least could with some mechanical coaching. And I bet if those guys who can jump over cars had some basic sprinting training and developed the coordination and mechanics they could get fast very quickly.
My point is that one serves the other. Does having a 200kg power clean mean that you will run sub-10? No. Does every elite sprinter have an elite power clean? No. But there is a certainly a correlation (please omit “But Bolt… But LeMaitre…” arguments).
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Can you define ‘correlated’ Alex?.
Usually the top 15 in the vert can’t get into the top 15 of the 40, and vice-versa.
How much room for manoeuvre do we have in terms of correlation (before we say, wait a minute, something just doesn’t quite add up?). (Seems to be a lot).
If I run 4.25 in the 40 & hit 30′ for the vert, do we have a correlation?.
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Re:: jump or drop downs with a hold at the bottom. These are very important for developing the eccentric component of the stretch-shorten concept that is the basis for plyometric or explosive actions.
Jump height is related to fast twitch fibers. the higher the jump the greater the percentage of fast twitch fibers –all other factors being equal. Speed is also related to fast twitch fibers. Thus jump height can be used as an indicator of the athletes potential for speed. There are too many other technical and physical factors involved to see a direct correlation.
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In my experience Box jumps have their place in developing speed and vertical jumping ability and they do work when used within the right context, you just have to be careful about volume and timing related to whatever else you do in your program.
jumping onto a box has its use for starting power and it’s nice to have a target height sometimes just to challenge you to go higher and in a way force you to express more power.
box jumps,depth jumps or whatever you want to call it…i.e. stepping down from a box and jumping back up immediately have their use in developing vertical jumping ability and I still use’em to improve speed and power as a sprinter.
Altitude jumps,for me, are a total no go in either case as it teaches the body not to react to the stimulus but rather to absorb and disperse energy throughout your body instead of using the stretch reflex to your advantage and react.
It is quite easy to desensetize your system and you have no idea how fast you can f***up your system if you do it for only a few sessions.My question is do you want your muscles to adapt in away to learn to use elastic energy more efficiently or to be conditioned to become heavy duty dampers?
Some may have other opinions,but in my experience the only thing that altitude jumps are good for are for safety purposes such as making sure that you can land a drop properly before attempting box jumping from new heights.
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Can you define ‘correlated’ Alex?.
Usually the top 15 in the vert can’t get into the top 15 of the 40, and vice-versa.
How much room for manoeuvre do we have in terms of correlation (before we say, wait a minute, something just doesn’t quite add up?). (Seems to be a lot).
If I run 4.25 in the 40 & hit 30′ for the vert, do we have a correlation?.
If we take two guys on the same team who play the same position, are the same height, and weigh the same, but one has a 35″ vert and the other has a 25″ vert, I’d bet everything I own that the guy with the 35″ vert has a better 40yd time.
With you, I would say there is still a correlation. While a 4.25 40yd is elite, a 30″ standing vertical is still good by any standards. If you ran a 4.25 and had a 20″ vert, I’d say that would disprove the correlation. But I don’t think there is anyone out there with such a disparity between the two. Like Dr. Yessis said, they are both indicators of fast twitch fibers.
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In my experience Box jumps have their place in developing speed and vertical jumping ability and they do work when used within the right context, you just have to be careful about volume and timing related to whatever else you do in your program.
jumping onto a box has its use for starting power and it’s nice to have a target height sometimes just to challenge you to go higher and in a way force you to express more power.
box jumps,depth jumps or whatever you want to call it…i.e. stepping down from a box and jumping back up immediately have their use in developing vertical jumping ability and I still use’em to improve speed and power as a sprinter.
Altitude jumps,for me, are a total no go in either case as it teaches the body not to react to the stimulus but rather to absorb and disperse energy throughout your body instead of using the stretch reflex to your advantage and react.
It is quite easy to desensetize your system and you have no idea how fast you can f***up your system if you do it for only a few sessions.My question is do you want your muscles to adapt in away to learn to use elastic energy more efficiently or to be conditioned to become heavy duty dampers?
Some may have other opinions,but in my experience the only thing that altitude jumps are good for are for safety purposes such as making sure that you can land a drop properly before attempting box jumping from new heights.
I thought the logic behind altitude jumps (I was taught to call them “drop jumps”) was to train the eccentric elements of sprinting? You do raise a good point though.
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Like Dr. Yessis said, they are both indicators of fast twitch fibers.
Granted, they are both indicators of fast twitch fibers, but I still can’t justify a correlation between vert & speed.
The top 15 vert guys & not one places in the top 15 in the 40.
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My question is do you want your muscles to adapt in away to learn to use elastic energy more efficiently or to be conditioned to become heavy duty dampers?.
Again people associating muscle with elasticity?.
Elasticity is predominately in tendons & the fascia.
What is the optimal way of developing tendons?. Would I be right in saying long-duration isometrics?. ie. a world apart from plyo’s & tendon vibration (possible reduction in plantar flexion force).
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Elasticity is nothing without sufficient eccentric strength.
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Quasi isometric (eccentric strength) is crucial in developing tendon elasticity
A Vert has a great amount to do with using the QI state of the quads and the concentric power of the glutes, hams and calfs along with the elasticity of the achilies very similar to top speed running, not acceleration which requires more concentric involvement of the quads.
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There is a world of difference between a depth jump and a box jump. the gains from each will not be applied equally to different sports.
In regard to altitude jumps these are extremely important in preparing you for plyometric jumps. They have a dampening role only if you drop down low enough to absorb all of the energy created. The main use is to withstand and accumulate energy in the eccentric contraction. It should be used by all athletes who have weak eccentric strength. They can be used concurrently with other jumps to maintain and improve the elasticity or rebound effect.
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Elasticity is nothing without sufficient eccentric strength.
Quasi isometric (eccentric strength) is crucial in developing tendon elasticity.
Could either of you please link me to verify these quotes?.
I was at the understanding that only long duration isometric contractions were optimal in developing the elasticity of human tendon structures with no eccentric/concentric phases.
The diagram below states eccentric is the worst form of contraction for the tendons.
Original Link: https://maximum-maximorum.com/2010/07/29/sprinting-and-the-muscle-tendon-complex-mtc/
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quasi eccentric is effectively an isometric contraction, that is a slow eccentric.
Reasoning for eccentric training being better is its influence in makeing the muscle ‘stiffer’ which inturn influences the Tendon.
when a force is absorbed, the most compliant element is the one that takes the energy. as muscle is the worst for returning energy you want this to therefore be the Tendon that takes the force. a strong muscle (mostly influenced by heavy training (good emphasis on eccentric training) which will then put the tendon at the forefront of the action.
Remember though that you still want a ‘stiff’ tendon in order to create as much ‘bounce’ as possible
Hope that makes sense
2 years ago I had an athlete who had hyper mobility was running 11.5 I worked hard over the winter with him on the exact stuff above the next year he ran 10.9 fat, he has now quit training due to relationship issues (hoping to talk him into training again this winter) incidently his vert was huge, but top end was awful intil we worked this stiffness principle
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Can you define ‘correlated’ Alex?.
Usually the top 15 in the vert can’t get into the top 15 of the 40, and vice-versa.
How much room for manoeuvre do we have in terms of correlation (before we say, wait a minute, something just doesn’t quite add up?). (Seems to be a lot).
If I run 4.25 in the 40 & hit 30′ for the vert, do we have a correlation?.
“Correlation” is not something you feel or manoeuvre(sp) around. It is a statistical numeric. And there is no doubt that numerous studies (look them up yourself) have found a significant degree of correlation between maximum strength (squat), vertical jump and 40yd dash time (and even better correlation in shorter distances) especially when corrected for body weight. You can’t look at selected data points, or even selected ranges (top 15) and simply determine that a significant correlation doesn’t exist. And…the information and diagrams posted on Maximum-Maxorum (while very interesting), along with a great deal of the Soviet literature, is not science. Most of it is not peer reviewed and a great deal of it lacks the data to support many of the statements and claims made by the various authors. I like the Soviet literature, by the way, I’m just saying you can’t take every statement made in every piece of Eastern literature, or a website, as gospel, especially if you can’t see a word-for-word translation yourself AND are familiar with the methods, measurements, and peer review systems employed.
Having said that all that, my peronal opinion is that box jumps, including weighted box jumps, are a great tool, expecially for those that choose not to perform Olympic lifts. We use weighted vest box jumps in lieu of jump squats, which I think pose more risk to the spine. Altitude drops and reactive jumps (I include bounds here) are intense plyometric exercises which we also use, but more sparingly due to the intense nature of the exercise. As I’ve said many times, I personally like to hit many point on the force-time curve, and I use weighted box jumps and reactive jumps, along with sled pulls and steep hill sprints, to fill the gaps between squats, Olympic lifts, and sprinting. One caveat…we focus on football speed, so Max V is not nearly as important to us as it is to a sprinter.
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Quasi eccentric is effectively an isometric contraction, that is a slow eccentric.
COV, specifically in terms of the calf raise exercise whether trained in either a standing or seated position, how does performing a ‘quasi eccentric’ calf raise differ from a long-duration ISO (concentric) calf raise held for time (5mins)?.
Obviously some lowering eccentric phase?.
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And there is no doubt that numerous studies (look them up yourself) have found a significant degree of correlation between maximum strength (squat), vertical jump and 40yd dash time (and even better correlation in shorter distances) especially when corrected for body weight.
Then explain why not one athlete that excelled in the vert could not replicate the same excellence during the 40?.
I’m finding it hard to see the significant degree of correlation here?.
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research studies can also be misleading. If a box jump is used for development of explosive power, there is a powerful forced involuntary contraction of the muscle. There is hardly any change in muscle length and most of the shortening takes place in the tendon.
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[quote author="star61" date="1310763610"]And there is no doubt that numerous studies (look them up yourself) have found a significant degree of correlation between maximum strength (squat), vertical jump and 40yd dash time (and even better correlation in shorter distances) especially when corrected for body weight.
Then explain why not one athlete that excelled in the vert could not replicate the same excellence during the 40?.
I’m finding it hard to see the significant degree of correlation here?.[/quote]You don’t see the correlation unless you calculate it using the entire population of athletes. Have you calculated a Pearson product-moment correlation coefficient, or better yet the coefficient of determination? If not, how can you comment on the lack of correlation?
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research studies can also be misleading. If a box jump is used for development of explosive power, there is a powerful forced involuntary contraction of the muscle. There is hardly any change in muscle length and most of the shortening takes place in the tendon.
I think the contraction in a box jump would be voluntary, wouldn’t it? And is ALL explosive power dervied from the stretch shortening cycle?
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You don’t see the correlation unless you calculate it using the entire population of athletes. Have you calculated a Pearson product-moment correlation coefficient, or better yet the coefficient of determination? If not, how can you comment on the lack of correlation?
But where getting a decent degree of athletes at the combines every year. These guys are not your average athletes. Year after the year it seems the same pattern is emerging, guys excelling vertically can’t hold there own when it comes to excelling horizontally (Accelerating/sprinting).
There must be something in the verters arsenals/training methods that is impeding there potentials in gaining a 40yd placing?.
We only see a correlation when the top 10 verters hold the top 10 places in the 40. Then we have a correlation.
We don’t have nothing close to a correlation.
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I think the contraction in a box jump would be voluntary, wouldn’t it? And is ALL explosive power derived from the stretch shortening cycle?.
Does the stretch-shortening cycle (SSC) still hold water when muscles supposedly only work isometrically during ground contact?.
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…We only see a correlation when the top 10 verters hold the top 10 places in the 40. Then we have a correlation. We don’t have nothing close to a correlation…
This is absolutely baseless and totally untrue. You could have an extremely high degree of correlation even if a top 10 40 guy never made the top 10 in VJ and vice-versa if the population is big enough, and it is. The correlation may be nonlinear. It wouldn’t surprise me even if the curve was sigmoidal, with the slowest and poorest jumpers not correlating due to poor technique and coordination, and the fastest and highest jumpers not correlating because they are at the extreme end of performance. Even so, a high degree of correlation could exist. Again, correlation is a mathematical function that has to be statistically calculated, not something that can be eyeballed, especially if you’re only looking at one subpopulation (the top 10).
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Does the stretch-shortening cycle (SSC) still hold water when muscles supposedly only work isometrically during ground contact?.
They’re stiff, not rock hard, and the stretch reflex certainly applies to tendons as well. I’m not sure how much energy is stored where, whether its simply a potentiation effect, or if its a case of extending the time under tension (cheating the force time curve) but there is a reactive component…it can be measured. My question was, is all explosive power due to stretch reflex? I think not, as the second pull of a clean, or an all out squat jump, is explosive with little stretch-shortening involved.
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Isn’t it a stretch to expect Top 10’s in both categories to be identical for correlation to exist?
JC Cooper brings up a good point about training. Perhaps there are some who get a steady diet of 10’s and 20’s but not enough 20-40 work thus effecting their acceleration? Perhaps those who aren’t strong VJ’ers need more exposure to MxStr?
Years back, I do remember Poliquin saying that training for VJ improves sprint times but that training for sprints won’t improve VJ.
I would be interested in seeing VJ compared to 10 yard splits in a 40.
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This is possibly turning into the best thread in a long time!
Can we try looking at this holistically perhaps? Were looking at the ssc and isometric/quasi eccentric training of the quads but what are everyone’s thoughts on calf, hamstring, glutes, ES. Looking at the joint action when vert jumping and even sprinting in order to get the most out of tendon energy return, thoughts?
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[quote author="JC Cooper" date="1310788179"]
Does the stretch-shortening cycle (SSC) still hold water when muscles supposedly only work isometrically during ground contact?.They’re stiff, not rock hard, and the stretch reflex certainly applies to tendons as well. I’m not sure how much energy is stored where, whether its simply a potentiation effect, or if its a case of extending the time under tension (cheating the force time curve) but there is a reactive component…it can be measured. My question was, is all explosive power due to stretch reflex? I think not, as the second pull of a clean, or an all out squat jump, is explosive with little stretch-shortening involved.[/quote]
I agree with the squat jump component (very important in acceleration) but are you saying the second pull has no or little SSC component?
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[quote author="star61" date="1310804977"][quote author="JC Cooper" date="1310788179"]
Does the stretch-shortening cycle (SSC) still hold water when muscles supposedly only work isometrically during ground contact?.They’re stiff, not rock hard, and the stretch reflex certainly applies to tendons as well. I’m not sure how much energy is stored where, whether its simply a potentiation effect, or if its a case of extending the time under tension (cheating the force time curve) but there is a reactive component…it can be measured. My question was, is all explosive power due to stretch reflex? I think not, as the second pull of a clean, or an all out squat jump, is explosive with little stretch-shortening involved.[/quote]
I agree with the squat jump component (very important in acceleration) but are you saying the second pull has no or little SSC component?[/quote]
Done well/right, the second pull usually elicits a quick, powerful SSC through the so-called “double-knee bend”.
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I think we need better clarification of some terms. This is why I requested early on a definition of what is meant by box jumps etc. The way I see most people do box jumps, they are not explosive in nature. Thus what occurs to the muscles and tendons is different from what would occur on explosive jumps as in depth jumps — as defined by Verkhoshansky as the shock method.
In explosive (plyometric) jumps the contraction must be involuntary. To have a voluntary contraction takes much too long which negates the explosive component.
In regard to the isometric contraction it can be used for explosive actions but the mechanism would be different from what occurs in the isometric contraction in the switch from the eccentric to the concentric. here there is always a momentary isometric contraction when the movement stops in one direction and then starts in the other.
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According to Soviet/Russian research there is a direct positive correlation between strength and speed but only with the young and lower level athlete. there is a negative correlation with the high-level athlete. But we should not confuse high-level athlete with combine athletes. Those who will do well in the combine do not necessarily do well in gameplay — in fact few do. The main reason for this is that most combine tests do not measure (are not specific to) what the athlete does in gameplay.
For anyone interested in correlations I strongly recommend reading Bondarchuk’s books on Transfer of Training. he studied the top 25 athletes in the world in various events and correlated what they did in specific exercises and where they ranked in relation to their performance. It also substantiates my above comments. How well you do in specific tests does not always correlate to how well you do in the sport especially in regard to the different levels of athlete.
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Isn’t it a stretch to expect Top 10’s in both categories to be identical for correlation to exist?.
When I read comments such as: “also its very important to understand that in sprinting, vertical force production is the key to horizontal velocity”, then yes I expect a major correlation to exist (or at least more of a correlation than what we are seeing particularly with the standard of athlete that turns up at the combines).
Lets say only 3 of the top 15 verters placed within the top 10 40 table. I still wouldn’t associate that with a correlation. These are the guys with the greatest vertical force production (“the key to horizontal velocity”) don’t forget.
Not one can make it.
Perhaps there are some who get a steady diet of 10’s and 20’s but not enough 20-40 work thus effecting their acceleration? Perhaps those who aren’t strong VJ’ers need more exposure to MxStr?.
I’m almost certain the top verters will just put in as much speed work as the guys placing highly in the 40 table.
I’m at the belief there could be range of factor(s), such as mass, height, training methods, exercise preference, maybe the verters are quad dominant, maybe too much squatting or too much emphasis placed on oly’s etc (I don’t know I don’t have the answer), that is impeding them to produce a good 40 time. There must be something there doing in training/lifestyles which is producing a negative affect on there speed.
This is the thing & what the combine tables tell me. Train/emulate the vert guys, take up basketball.
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[quote author="cdnsprinter" date="1310628740"]My question is do you want your muscles to adapt in away to learn to use elastic energy more efficiently or to be conditioned to become heavy duty dampers?.
Again people associating muscle with elasticity?.
Elasticity is predominately in tendons & the fascia.
What is the optimal way of developing tendons?. Would I be right in saying long-duration isometrics?. ie. a world apart from plyo’s & tendon vibration (possible reduction in plantar flexion force).[/quote]
Burgess 2007
Isometric training increased gastrocnemius tendon stiffness by 61.6%
Plyomtric training increased gastrocnemius tendon stiffness by 29.4% but slightly higher baseChange to concentric jump height
-isometric +64.3%
-plyometric +58.6% but started at a higher baseChange to concentric RFD
-isometric +16.7%
-concentric +18.9% including start from higher base*Concentric jump performance significantly associated with tendon stiffness (r=0.46)
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BoingVERT – Official Jump Program of the Best Dunkers in the World.
https://www.youtube.com/watch?v=8ErM1OWB39c
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The comment that “its very important to understand that in sprinting, vertical force production is the key to horizontal velocity” is intriguing. If this were true why is it that world-class sprinters only displace their center of gravity about 1 inch while sprinting?
Also, how can you convert vertical force to horizontal speed? It’s possible to convert horizontal to vertical by I never heard of converting vertical to horizontal unless the force is directed horizontally.
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Any research on that? I have seen actual landmark data with motion analysis of 3 -4 inches.
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[quote author="cdnsprinter" date="1310628740"]My question is do you want your muscles to adapt in away to learn to use elastic energy more efficiently or to be conditioned to become heavy duty dampers?.
Again people associating muscle with elasticity?.
Elasticity is predominately in tendons & the fascia.
What is the optimal way of developing tendons?. Would I be right in saying long-duration isometrics?. ie. a world apart from plyo’s & tendon vibration (possible reduction in plantar flexion force).[/quote]
you are right,I used the term losely, I should have said muscle-tendon complex.
the best ways I used to develop tendons are heavy negatives,explosive heavy partials(up to 130% of 1RM)and plyo.Is there a better method?I don’t know,I’m no scientist. I’m just sharing what worked well for me performance-wise as an athlete
As for the optimal way of developing a tendon, I’d say it depends on what quality you want to improve? do you want to lengthen the tendon?strengthen the tendon or more stiffness? better elasticity or reactivity?
The other thing is that being able to sustain tension doesn’t automaticaly mean better performance.
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There is a world of difference between a depth jump and a box jump. the gains from each will not be applied equally to different sports.
In regard to altitude jumps these are extremely important in preparing you for plyometric jumps. They have a dampening role only if you drop down low enough to absorb all of the energy created. The main use is to withstand and accumulate energy in the eccentric contraction. It should be used by all athletes who have weak eccentric strength. They can be used concurrently with other jumps to maintain and improve the elasticity or rebound effect.
agreed as it should be a step to learning box jumps later, but besides for beginers I wouldn’t put any experienced athlete on a 3-4 week program that includes altitude jumps like once a week for example as it just teaches you not to jump.
have you ever seen an athlete alone on a fastbreak going for a dunk…one step, two step, going for a two footed jump and just NOT takeoff or barely crumble?
because his system has been deconditionned to store that energy and use it immediately in the opposite direction or conditionned to absorb tremendous forces and disperse energy throughout the body or as heat…it happened to me and other people I know.At one point we were landing 60+inch altitude jumps no problem with good technique but were unable to jump back up immediately between 20% and 50% of the time while doing 18 inch box jumps and it took a few weeks of reconditionning after stoping altitude jumps to get rid of that issue.
IMO,once you are strong enough to perform box jumps safely and proficiently,doing altitude jumps is like learning a bad habbit.
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I believe one problem that exists for many sprinters is that many of us are all trying to increase our verts. I always keep an open mind & it’s open to the fact there could be a link/training method/exercise etc which could possibly impede our true speed potentials. Maybe I’m looking too much into the combine results, who knows.
Altitude Jumps?.
https://www.youtube.com/watch?v=VRFsVAmYeLQ
If I start jumping off the house roof, can I begin to dream of the 100m WR?. Will higher altitudes produce better results?.
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as for the debate regarding sprinting speed and VJ correlation.
I agree that it takes similar attributes such as fiber type,power,elasticity,stiffness,strong core and etc…
is there a direct correlation or potential to be or become successful at the complementary task ? IMO up to a certain point yes, since the basics qualities needed are the same…but not without very specific skill training for each,let me explain myself:
we are comparing two similar but very different skills at the same time
-standing VJ is tested while jumping on both legs VS running on alternate legs…major difference here in mechanics to begin with, though the muscles you are using may be the same, they are not used in the same fashion and the demands on each of these muscle groups are not in the same proportion for both skills
-standing VJ is one maximal effort VS running is a succession or maximal(or increasing) efforts
-2 or 3 steps approach VJ is 2-3 submax contractions and horizontal displacement followed by one maximal effort converted onto the vertical plane.
-GTC is relatively much longer with VJ wether it’s 1 or 2 footed jumps relative to foot contacts in sprinting(at max V) where the goal is to sustain or try to increase velocity for successive bouts.
-when jumping you are using slightly a different area of the power curve then when sprinting
-just as it is important to have great technique to run fast, there are several technical tips you can implement with training to jump higher as well
-acceleration and max V mechanics are different too
-same for jumping: standing VJ is different from jumping coming from a runoff…some have little to no difference in standing VJ vs jumping from a runoff and some others have huge differences.
-jumping is a skill just as sprinting is a different skill,both must be developed and nurtured once you attain a certain level if you don’t want to lose some of that skill.All things aside, while both skills may be somewhat complimentary or related, in the past I’ve never been able to observe a direct increase in VJ right after putting more emphasis on sprint training.I’ve experienced a more direct or observable transfer from increasing VJ to improving running speed(acceleration).
But do I think that it helped raise my power curve in order to eventualy become better at one skill or the other, definately.
One thing could be said though:was I closer to my full or real potential with VJ than with running speed at that particular point in time? same question could be posed for anybody…how do you really know?
Will being great at one mean you will be good at the other? probably.
Will being great at one mean that you will be great at the other? not without specific training and for long enough.
Can you be great at both at the same time?depends at what you consider as being great too?but why not?
Can you be great at both in a lifetime?definitely. -
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[quote author="star61" date="1310804977"][quote author="JC Cooper" date="1310788179"]
Does the stretch-shortening cycle (SSC) still hold water when muscles supposedly only work isometrically during ground contact?.They’re stiff, not rock hard, and the stretch reflex certainly applies to tendons as well. I’m not sure how much energy is stored where, whether its simply a potentiation effect, or if its a case of extending the time under tension (cheating the force time curve) but there is a reactive component…it can be measured. My question was, is all explosive power due to stretch reflex? I think not, as the second pull of a clean, or an all out squat jump, is explosive with little stretch-shortening involved.[/quote]
I agree with the squat jump component (very important in acceleration) but are you saying the second pull has no or little SSC component?[/quote]It depends on how its done. Some coaches do not teach the double dip, and many videos I see of top lifters show little to no evidence of a dip, just a slight pause in the extension phase.
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Participant
Ok I have a spreadsheet with an entire combines worth of data so I feel the need to chime in. Using basic linear regression I get the following:
40 and vertical: -.74
Weight and 40: .87
Weight and vertical: -.61So to interpret for JC cooper, it means as 40 time goes down, vertical goes up. As weight goes up, 40 goes up. And as weight goes up, vertical goes down. These are HIGHLY correlated based on 2-300 data points. It’s not debatable. The strongest relationships in order are: weight and 40, 40 and vertical, weight and vertical.
So for a rudimentary conclusion, I can say this. The reason the highest vertical guys aren’t the fastest runners in the NFL is simply a function of weight. Vertical is more dependent on absolute power and every NFL athlete has the potential to succeed at it. The 40 time is more reliant on relative power among other more specialized adaptations. If you look at the link JC Cooper posted, the top performer is a tight end and a defensive lineman is number two. We also have a quarterback tied at number eight. That won’t be happening in the 40. Notice the top 15 guys only come from three positions: RB, WR, CB.
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Participant
[quote author="Carl Valle" date="1310841848"][quote author="star61" date="1310804977"][quote author="JC Cooper" date="1310788179"]
Does the stretch-shortening cycle (SSC) still hold water when muscles supposedly only work isometrically during ground contact?.They’re stiff, not rock hard, and the stretch reflex certainly applies to tendons as well. I’m not sure how much energy is stored where, whether its simply a potentiation effect, or if its a case of extending the time under tension (cheating the force time curve) but there is a reactive component…it can be measured. My question was, is all explosive power due to stretch reflex? I think not, as the second pull of a clean, or an all out squat jump, is explosive with little stretch-shortening involved.[/quote]
I agree with the squat jump component (very important in acceleration) but are you saying the second pull has no or little SSC component?[/quote]It depends on how its done. Some coaches do not teach the double dip, and many videos I see of top lifters show little to no evidence of a dip, just a slight pause in the extension phase.[/quote]
This is true, but here is the data from WC.
All athletes from WC did a DKB. The snatch had less DKB. The lighter weight classes had less.
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Participant
Ok I have a spreadsheet with an entire combines worth of data so I feel the need to chime in. Using basic linear regression I get the following:
40 and vertical: -.74
Weight and 40: .87
Weight and vertical: -.61So to interpret for JC cooper, it means as 40 time goes down, vertical goes up. As weight goes up, 40 goes up. And as weight goes up, vertical goes down. These are HIGHLY correlated based on 2-300 data points. It’s not debatable. The strongest relationships in order are: weight and 40, 40 and vertical, weight and vertical.
So for a rudimentary conclusion, I can say this. The reason the highest vertical guys aren’t the fastest runners in the NFL is simply a function of weight. Vertical is more dependent on absolute power and every NFL athlete has the potential to succeed at it. The 40 time is more reliant on relative power among other more specialized adaptations. If you look at the link JC Cooper posted, the top performer is a tight end and a defensive lineman is number two. We also have a quarterback tied at number eight. That won’t be happening in the 40. Notice the top 15 guys only come from three positions: RB, WR, CB.
Derrick, thanks for the info, great job.
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Participant
Carl, I’ve seen several studies that show that the vertical displacement of the center of gravity in world-class runners is only about 1 inch. These articles appeared in the Fitness and Sports Review International.
Even if it were 2 to 3 or 4 inches it still does not indicate that the vertical component is most important in producing horizontal speed. Thus the question remains, how is the vertical component converted to horizontal?
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Participant
Regarding the altitude jump. In the altitude jump that I learned from the Russians, who I believe were some of the first ones to use this method, you do not jump up after the drop down and hold. As I mentioned previously it is used to develop the eccentric component of the SSC.
It is not used year round and not during the season. Thus it does not interfere with any speed work. It is just another method – just as weight training is. Doing maximum resistance squats without concurrent explosive work can also lead to slowness.
In this regard box jumps can also be a negative because they do little if anything to improve explosive power.
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Participant
Carl, I’ve seen several studies that show that the vertical displacement of the center of gravity in world-class runners is only about 1 inch. These articles appeared in the Fitness and Sports Review International.
Even if it were 2 to 3 or 4 inches it still does not indicate that the vertical component is most important in producing horizontal speed. Thus the question remains, how is the vertical component converted to horizontal?
I always thought that it is the vertical “emphasis” that is important at top speed, due to the forward moving COM. If the foot contacts at directly below the COM (to reduce braking, prevent loss of hip height, etc) then given the forward motion of the body the foot will be behind the body throughout the stance phase as the hip goes into full extension. While the power was aimed straight down, it is actually applied on a forward angle due to the forward moving COM.
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Participant
Carl, I’ve seen several studies that show that the vertical displacement of the center of gravity in world-class runners is only about 1 inch. These articles appeared in the Fitness and Sports Review International.
Even if it were 2 to 3 or 4 inches it still does not indicate that the vertical component is most important in producing horizontal speed. Thus the question remains, how is the vertical component converted to horizontal?
Dr. Yessis,
In order to get horizontal speed you need to handle the first and constant issue of gravity. Then through the hips they are projected forward and if you had access to the footage I have (and posted) you would see that toe off has no contribution.
If you can share the Fitness and Sports Review via pdf of what athletes were tested and how were they measured.
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Participant
Josh wrote: I always thought that it is the vertical “emphasis” that is important at top speed, due to the forward moving COM. If the foot contacts at directly below the COM (to reduce braking, prevent loss of hip height, etc) then given the forward motion of the body the foot will be behind the body throughout the stance phase as the hip goes into full extension. While the power was aimed straight down, it is actually applied on a forward angle due to the forward moving COM.
Prior to touchdown the leg should be moving backward. Thus the forces generated at contact or not vertical, they are mostly horizontal. The forces are given back via ankle extension when as you stated,the body is well in front of the foot. Thus all the forces are mostly horizontal not vertical. I explain this in great detail in the second edition of my book Explosive Running.
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Participant
Carl wrote: Dr. Yessis,
In order to get horizontal speed you need to handle the first and constant issue of gravity. Then through the hips they are projected forward and if you had access to the footage I have (and posted) you would see that toe off has no contribution.
There’s no questioning the fact that gravity is involved but it is a constant factor. The runner has to have the strength needed to not allow gravity to lower his body too much during contact.
I agree that the forces then have to be projected through the hips but it is not the force of gravity. It is the force generated by the ankle joint extension in the pushoff.
From your comments I know you disagree with this but please direct me to some of your footage and if it is of legitimate runners I may be able to show you that ankle joint extension is the key action. You may also wish to look at the sequential pictures that I have in the second edition of my book Explosive Running that were taken from live digital film of world-class and high-level runners. All of them show how ankle joint extension is the key propulsive force in the pushoff.
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Participant
Dr. Yessis,
Contributions from plantar flexors yes eccentric to concentric forces …at toe-off no. The contributions of stored elastic power are earlier than running with sprinting. Hence why the windlass data is mainly for walking.
Your book doesn’t have any elite 100m dash sprinter I am aware of…..what where their times?
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Participant
Has anyone seen the full text of the article below? I’m curious to know what the actual force vectors were. How much of the total force is expressed in the vertical vector and how much in the horizontal vector? Also, any similar studies? This study indicates that very little increase in vertical force, about 15%, is needed to go from 60%MaxV to 100%MaxV, and only 1% increase in vertical forces to go from 80%MaxV to 100%MaxV. This supports what many believe…that vertical forces are most important in early acceleration and drive phase. This is why vertical exercises, like squats and jumps, improve short sprint time but not MaxV. Which leads to the million dollar question…what exercises improve horizontal force production at MaxV (besides unresisted MaxV sprinting)?
Brughelli, M, Cronin, J, and Chaouachi, A. Effects of running velocity on running kinetics and kinematics. J Strength Cond Res 25(4): 933-939, 2011
Sixteen semiprofessional Australian football players performed running bouts at incremental velocities of 40, 60, 80, and 100% of their maximum velocity on a Woodway nonmotorized force treadmill. As running velocity increased from 40 to 60%, peak vertical and peak horizontal forces increased by 14.3% (effect size [ES] = 1.0) and 34.4% (ES = 4.2), respectively. The changes in peak vertical and peak horizontal forces from 60 to 80% were 1.0% (ES = 0.05) and 21.0% (ES = 2.9), respectively. Finally, the changes in peak vertical and peak horizontal forces from 80% to maximum were 2.0% (ES = 0.1) and 24.3% (ES = 3.4). In addition, both stride frequency and stride length significantly increased with each incremental velocity (p < 0.05). Conversely, contact times and the vertical displacement of the center of mass significantly decreased with increased running velocity (p < 0.05). A significant positive correlation was found between horizontal force and maximum running velocity (r = 0.47). For the kinematic variables, only stride length was found to have a significant positive correlation with maximum running velocity (r = 0.66). It would seem that increasing maximal sprint velocity may be more dependent on horizontal force production as opposed to vertical force production.
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Participant
Carl wrote: Contributions from plantar flexors yes eccentric to concentric forces …at toe-off no. The contributions of stored elastic power are earlier than running with sprinting. Hence why the windlass data is mainly for walking.
Your book doesn’t have any elite 100m dash sprinter I am aware of…..what where their times?
Carl: I don’t understand how you can say no at toe off. This action is completed in less than 0.10 seconds. If the forces are released sooner, how much sooner and what is the purpose of this? What do you mean by windlass data? Everything I’ve said up to this point is related to sprinting. It has nothing to do with walking.
In my book Explosive Running I do not have any sub 10 second runners but I do have two 10+ runners. Their technique is not different from those of sub 10 second runners. Nor are they much different from 200 400 and even 800 m runners. Thus their exact times are immaterial when it comes to analyzing technique for the majority of all coaches. Have you read the book?
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Participant
Dr. Yessis,
I have read both Ralph Mann’s studies and books and yours. The data collected by Ralph Mann is what I side with because I am more of numbers person than an explanation person.
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Participant
even if the kinematics tell us that less force is needed this a mechanical model that does not take into account the physiological properties of the human body.
RFD and reactive strength are very important factors here, that have higher correlation with MaxV speed than maximum force production.
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Participant
Surely vertical force production is crucial at maxV?
Newtons laws of motion, any object in motion will continue in motion unless an external force is applied, gravity?
So we have to add a vertical force production in order to minimise the slowing nature of gravity.
As our COM is slightly ahead of the physical body in full sprint flight then this where the horizontal requirement is required, no?
Carl/ Michael I think you should confirm to which part of the stride cycle and stating the energy is returned. Carl i would side your your statement that the eccentric/iso/concentric energy return is (at the least the largest proportion) done so much sooner then ‘toe off’ at full triple extension.
However, I can see where Michael thoughts are in the biomechanics model of the ‘throw’ full energy release is at the end of all extended joints, this case being triple extension
Similar to throwing a ball, you release the power at the end of full should elbow wrist hand extension. But as the leg encounters an external load mid ‘throw’ the greatest power output has to be at the point.Hope I made sense there.
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Participant
I am not concerned about stride length or stride frequency or vertical vs horizontal needs as much as the kinematic and kinetic results of training preparing for meets. With all of this data does anyone think Bolt and Asafa train differently in the weight room?
Dr. Yessis is making good points but I think elites have some data that looks paradoxical. For example I believe hip height with 9.7 guys is less than 9.9 guys.
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Participant
Several important points have been raised in the last few comments. I would like to address each one separately.
first Carl you wrote that: I have read both Ralph Mann’s studies and books and yours. The data collected by Ralph Mann is what I side with because I am more of numbers person than an explanation person.
I’m surprised at your response mainly because in all valid research the researchers must be able to explain why they got the results that they did. If they cannot explain them then it is back to the drawing board regardless of what the numbers may seem to indicate.
Second, since you read my book perhaps you (or anyone else in his group) can tell us where I am wrong in my explanation of the role of the ankle in the push-off. My explanations are based on what I see in live-action and I substantiate all of my comments with biomechanical and kinesiological data together with the exact photographs that illustrate and substantiate my comments. Recall that all the photographs have been taken from live digital film. In other words everything I stated can be substantiated. If I am wrong please bring out exactly where.
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Participant
Rune stated that even if the kinematics tell us that less force is needed this a mechanical model that does not take into account the physiological properties of the human body.
RFD and reactive strength are very important factors here, that have higher correlation with MaxV speed than maximum force production.
ProfileRune when you refer to the kinematics is this in relation to the ankle joint extension? If yes what is it less than? The knee joint? the hip joint? We are dealing with physiological properties here not simply mechanical. It is the reactive force that the ankle joint extension generates.
Isn’t RFD and reactive force during the support phase in running the same? if not please explain.
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Participant
COV wrote: “Surely vertical force production is crucial at maxV?
Newtons laws of motion, any object in motion will continue in motion unless an external force is applied, gravity?
So we have to add a vertical force production in order to minimise the slowing nature of gravity”.
for the most part vertical force is not crucial at MaxV. sprinters want to minimize vertical force as much as possible and generate the maximum amount of horizontal force. The higher they displace their center of mass the more wasted energy they have in order to get up higher in the air. They want the energy used to go horizontally not vertically! Gravity is a constant factor in running — there is no separate application of it
COV wrote that “As our COM is slightly ahead of the physical body in full sprint flight then this where the horizontal requirement is required, no?
no the COM is not ahead of the body. you push it forward in the pushoff — this is where the horizontal requirement is required.
COV stated that: Carl/ Michael I think you should confirm to which part of the stride cycle and stating the energy is returned. Carl i would side your your statement that the eccentric/iso/concentric energy return is (at the least the largest proportion) done so much sooner then ‘toe off’ at full triple extension.
there is only one place that energy can be returned and that is in the ankle joint extension. It is the ankle that gets loaded returns the elastic energy. I must also take issue with your statement that it occurs sooner at full triple extension.there is no full triple extension! If you don’t see this in films I strongly recommend you take a look at the pictures in my book Explosive Running. When you view a film the action happens too fast and you cannot see what occurs in each joint.look at the pictures and you will see.
COV wrote that “However, I can see where Michael thoughts are in the biomechanics model of the ‘throw’ full energy release is at the end of all extended joints, this case being triple extension
Similar to throwing a ball, you release the power at the end of full should elbow wrist hand extension. But as the leg encounters an external load mid ‘throw’ the greatest power output has to be at the point.”you are wrong in your belief that my thoughts are in a biomechanics model. I’m not talking about a model. I am talking about exactly what happens in the running stride taken from actual film of high-level runners. Rather than using comparisons that don’t apply it would be better if you could explain where the leg encounters an external load in the “middle” and what purpose it serves.
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nice discussion
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Admittedly, I’m out of my league here…and probably am not qualified to enter this discussion 🙂 I apologize in advance…
for the most part vertical force is not crucial at MaxV. sprinters want to minimize vertical force as much as possible and generate the maximum amount of horizontal force.
It’s my understanding (again, limited) that once an athlete is at Max Velocity – the majority of the force application required to maintain this velocity becomes vertical. As the body is already at max velocity, no more increases in horizontal velocity are possible (hence the term “maximum” velocity). So only the horizontal forces necessary to maintain this velocity would be required? As the primary inhibitor to horizontal velocity would appear to be air resistance – the athlete would only then have to apply enough horizontal force to counter this resistance (and pray for a tail wind…hah, hah).
As contact time (the only time to apply force) decreases as velocity increases, and ultimately serves as a limiting factor at max velocity (when it’s at it’s minimum), the majority of force application time would seem best used to lift the body’s center of mass against gravity (a vertical phenomenon)in order to create the required flight time to cycle the legs for the next force application. Likewise, upon foot contact, would not another vertical force be required to keep the body from collapsing at landing at the end of the fall from a parabolic flight(again gravity)?
I guess I always thought that the ground contact time was so limited once an athlete reached max V – that they simply ran out of time to apply any additional horizontal forces to increase velocity. Simply the ground was moving too fast under their feet to apply the needed forces, leaving only time to apply the required horizontal forces to maintain momentum (and resist deceleration) and the rest was vertical (as noted above).
Again, I’m probably missing something (I should have taken physics I guess) and no doubt taking an overly simplified view of this. Isn’t gravity a greater force at max velocity than air resistance?
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Participant
I’m certainly out of my scientific league as well, however EVERY great sprint coach points out that vertical force is critical at max velocity and that you should not actively try to create horizontal force at max velocity. Are they wrong?
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Participant
Vertical force is crucial during the entire sprint, especially max velocity. When you’re running 12m/s it takes a lot of vertical force to get Asafa’s fat butt back off the track in .087 seconds…much more force than is does to negate the minimal braking due to a slightly in front COM touchdown and some air resistance. Sure there is horizontal force but it’s less than the vertical.
Hell the whole race probably demands more vertical force than horizontal. Gravity is a b**ch.
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Participant
I’m certainly out of my scientific league as well, however EVERY great sprint coach points out that vertical force is critical at max velocity and that you should not actively try to create horizontal force at max velocity. Are they wrong?
I think a lot of this stems from the Peter Weyand study. I’m not a big fan of his work so, in my opinion, there is certainly room for debate. As for which is more important, I think it is mostly irrelevant. You can’t cue an athlete to push backwards at maximum velocity because it will only slow them down. So in a sense, force at maximum velocity is essentially “vertical.” And the real force application could be different. But it does seem telling to me that stride length peaks before stride frequency and the highest stride frequency coincides with the fastest speeds. Horizontal forces are harder to apply with shorter ground contact times so take that for what it’s worth.
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Member
This is my understanding of the vertical forces issue: The key premise we are working with here is that at maxV, velocity remains constant. This means that there is no horizontal acceleration, and therefore the forces in the horizontal plane negate each other. Essentially, the positive horizontal acceleration applied during ground contact is equal only to the negative acceleration of braking forces during ground contact and air resistance, which are very small.
The issue of maintaining top speed is not about applying huge horizontal forces during ground contact, but minimizing breaking forces during ground contact by swinging the legs as fast as possible and minimizing ground contact time. As vertical forces applied increase, the athlete has greater vertical displacement and spends more time airborne. More time airborne means more time at that speed, and also less stride frequency is necessary to maintain top speed, reducing fatigue and allowing the legs to move faster and reduce ground contact times.
This, however, is from a purely textbook physics perspective. Of course races aren’t run on paper, athletes accelerate and decelerate small amounts throughout a run, and there are many biomechanical factors, etc., but I believe this is the reasoning behind the emphasis on vertical forces.
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Participant
I’m certainly out of my scientific league as well, however EVERY great sprint coach points out that vertical force is critical at max velocity and that you should not actively try to create horizontal force at max velocity. Are they wrong?
This is the most important quote of the thread. While the point of this was not to get into running mechanics and vertical and horizontal contributions, the drop from gravity isn’t high enough to need altitude jumps, the need to get into horizontal propulsion has less and less time has the speed increases. The tibial angle and forefoot set’s up the parabolic flight path (note very flat I may add) but like baseball throwing, wrist snap has very little propulsion to velocity. The same can be said about the toe off. Ironically the plantar flexors do contribute earlier and higher before toe off, but extension is more hip dominant.
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Participant
I agree, as with my analogy of the ‘throw’ in this case the triple ext ‘toe off’ adds very little to actual horizontal or even vertical propulsion.
This is due to an outside force being applied ‘mid’ throw, this of course is THE GROUND which you encounter way before you reach TE or toe off.
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Participant
I agree, as with my analogy of the ‘throw’ in this case the triple ext ‘toe off’ adds very little to actual horizontal or even vertical propulsion.
This is due to an outside force being applied ‘mid’ throw, this of course is THE GROUND which you encounter way before you reach TE or toe off.
I started a new thread on ground contact for everyone to focus on. If you want box jump discussion carry on but if you want to debate foot strike please continue to the new thread.
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Participant
” date=”1311065833″]Vertical force is crucial during the entire sprint, especially max velocity. When you’re running 12m/s it takes a lot of vertical force to get Asafa’s fat butt back off the track in .087 seconds…
Hell the whole race probably demands more vertical force than horizontal.
But as a whole he’s still running horizontally across the ground, he’s not trying to dunk a basketball.
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Participant
All of them show how ankle joint extension is the key propulsive force in the pushoff.
That is a real biggie.
The 40 time is more reliant on relative power among other more specialized adaptations.
The 40 time is more reliant on relative power/limb speed (to lower bodyweight)?.
Is that what your initiating?.
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Participant
The ankle ‘complex’ is crucial in energy return and propulsion but it’s not at toe off !
Could the ankle complex be VERY critical to horizontal propulsion at Maxv?.
More so than what we credit it with?.
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Participant
The data was collected and no, at toe off the forces are minor. The quote above is clear. I can’t argue anymore as the information is accepted but then again some people don’t accept the science.
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Participant
It’s somewhat surprising to see so many of you agreeing that the vertical component is most important in maximum speed running where the vertical displacement of the center of mass is minimal. if you rely on the vertical production of force the center of mass will be raised much higher. In essence you will then look like you were jumping up and down as you move down the track. But in world-class runners you don’t see up and down, you see what appears to be only horizontal.
Many of you continue to state that the force from the ankle joint is minimal at toe off. This is true — there’s no questioning this and there is a very good reason for this. but yet no one has answered my question that if the ankle joint extension forces are applied sooner, as many have stated, where in the range of motion is it applied and in what direction is it applied? If you cannot answer this, how can you maintain that it occurs and that this is what happens or is most efficient?
How much force does it take to raise your body 3 inches off the ground? this is how much force has to be directed on a vertical vector. If you read my book Explosive Running you’ll get a more detailed description and explanation of what and why everything occurs. Perhaps after reading the book we can have an even more enlightening discussion.
As I stated earlier in one of my posts is necessary to be able to explain what research numbers mean in order to understand what takes place in running. because you have more force at touchdown and less at toe off shows great efficiency and is more substantiation for the production of horizontal force. You can test this yourself by standing on 1 foot on a scale.Then take a long forward stride but keep your foot on the scale. the difference now becomes obvious.
As someone stated earlier I believe it is Weyand who started this erroneous thinking. His one finding clouded his thinking in relation to everything else that occurs. Even to this day he admits that he does not know how the runner generates the force that he does on landing. if as he states that this is the most important factor in running, you would think he would be able to explain this. but he cannot. But yet he has many followers.
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Participant
I have the book.
The part which states; “during the push-off, the hip extensor muscles (gluteus maximus, hamstrings) do not contract to push you forward” should send alarm bells ringing through the industry.
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Participant
Force upon landing has been calculated at being upto 7 times that of the human body weight, without applying a vertical propulsion you would merely decend until your crawling.
The fact that there is little to no vertical displacement at sprint speed is merely due to:
a/ The equalling out of the gravitational force vector and contact force
b/ although the human force is applied vertically it is put through a cylindrical vector dur to limb length/Hip height and the already achived horizontal speed (obvious)
What your stating as being Horizontal propulsion is merely the combination of vertical force applied over a curved vector, it is the vertical energy absorbtion and return that is the key
Just my thoughts on the matter
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Participant
COV-GOD has it. You need to apply vertical forces first and if you do it well horizontal resultant force will follow. Note the emphasis on actual loading such us 7 times body weight.
Dr. Yessis,
Clearly you are sharing you opinion of observation. Many us are citing actual studies and biomechanical data with numbers and tables of forces and vectors. You are not.
I have read the book ten years ago and walked away with the same feelings I have now.
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Participant
I have the book.
The part which states; [i][b]“during the push-off, the hip extensor muscles (gluteus maximus, hamstrings) do not contract to push you forward”[/b][/i] should send alarm bells ringing through the industry.
What pages JC?
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Participant
[quote author="JC Cooper" date="1311149265"]I have the book.
The part which states; [i][b]“during the push-off, the hip extensor muscles (gluteus maximus, hamstrings) do not contract to push you forward”[/b][/i] should send alarm bells ringing through the industry.
What pages JC?[/quote]
Pages 17 & 18 Carl, Chapter 3 under the subheading: Pushoff.
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Participant
The 2011 edition doesn’t say that….what do you have again?
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Participant
It does. see page 23
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Dr. Yessis,
The 2011 edition doesn’t say that on page 23 either. Sorry .
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Participant
are you sure that you have the revised second edition of Explosive Running? All the copies we have on hand state this quite clearly on page 23 near the bottom.
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Participant
The Mechanics of Sprinting and Hurdling by Ralph V Mann 2011 is what I am talking about…..
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Participant
I certainly don’t have the 2011 edition.
Never knew there was one. How does it differ from the revised second edition Michael?.
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Participant
The Mechanics of Sprinting and Hurdling by Ralph V Mann 2011 is what I am talking about…..
lol.
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Participant
Carl, whenever I give an opinion I state that this is opinion. do you say I give opinions because you cannot dispute what I have said? What I have presented and have been talking about is all based on scientific fact not opinion. from my biomechanical and kinesiological backgroundI am very strong on observation and understanding of what takes place in the running stride. To me this is the most important for a coach. for example knowing that a high-level runner generates up to 1000 pounds of force on landing by itself means very little. It takes on great significance when the coach considers how his runners can generate this type of force. This knowledge can be put into practice to better the runner. But you must first understand not only how this force is generated but what happens to it after the landing.
From what I can gather from the above posts some of you believe that this force is given back and that’s why you need a vertical component. However most of this force is absorbed in the landing by a flexion in the ankle, knee and hip joints. A portion of it goes into loading the ankle joint for the pushoff.
You state that studies and “numbers” are presented to substantiate your statements. However I have not seen any to refute the facts what I have stated. I have raised many questions but they have not been directly addressed. I haven’t seen a single fact presented that refutes my statements. I have read quite a bit of opinion.just because something is said over and over again does not mean it is fact.
the goal here is to improve not only our knowledge of what occurs in the running stride but also how we can improve running performance. However in order to do this we must stay on point.
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Participant
sorry about the information on Explosive Running. Your original question asked for the pages on which my quote appeared.
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Participant
I myself am open for discussion and I am happy to learn and be taught.
However, Michael could you please also prove fact of your thoughts, not just by your own book
I don’t mean that in a derogatory manner just no one as yet has quoted fact on either side other than their own beliefs or that of other prom ant coaches, and mr Ralph Mann is certainly a promo ant source of information as is sea grave IMO
Thanks
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Participant
Runners do not push off the ground but fall forwards via a gravitational torque.
Romanov N, Fletcher G.
Poses Tech Corp, Coral Gables, Florida, USA.
Sports Biomech. 2007 Sep;6(3):434-52.Original Link: https://www.ncbi.nlm.nih.gov/pubmed/17933203
I don’t believe Michael’s book goes into detail regarding this “gravitational torque”.
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Participant
JC, the second edition of Explosive Running differs from the first edition mainly with the specialized strength and explosive exercises. I have improved some of the original exercises that were created to duplicate what occurs in the running stride and have added more equally effective exercises.I hope you used some of the exercises from the original book. if you did you should have seen significant improvement in your runners not only in regards to technique but also speed. there were also many smaller changes made in the other chapters.
In regard to Romanov and the pose method it pure fiction. this is why I did not bother going into it in my book.
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Participant
Dr. Yessis, is your Explosive Running 2nd edition available in ebook format by chance?
I think the trouble with some of the arguments in this thread is that I don’t believe any parties have read both your latest book and Mann’s latest work. I have the 1st edition of Explosive Running but not the 2nd.
It is difficult to argue against Mann’s conclusions as he has been employed to study the elites of USATF sprinting for the past 20+years and was an Olympic sprinter himself.
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Participant
COV-GOD, you stated, “However, Michael could you please also prove fact of your thoughts, not just by your own book
I don’t mean that in a derogatory manner just no one as yet has quoted fact on either side other than their own beliefs or that of other prom ant coaches, and mr Ralph Mann is certainly a promo ant source of information as is sea grave IMO.”
I would be happy to do this but only on one condition. When someone states a “fact” and it is questioned or someone asked for substantiation of the comment then the person who made the original statement should first substantiate that what he says is a true fact. if not, then we should just ignore what was said and move on
this is where the problem, as I see it, is. If you go back to all my posts you will see that few if any of my questions regarding the “facts” were ever responded to. Because a statement is made by a prominent author or coach does not mean that it is fact. We should be able to question anyone in regard to the statements that are made and more importantly, they should be able to back up what they say. if not, we can then assume it is only their opinion, not fact. note also that this is the basis for a valid and fruitful discussion.
We should also define our terms. if you look at one of my very first posts on this topic in regard to box jumps and depth jumps I asked for a definition of what was meant by these terms. I never got one. It is as though everyone knows what the terms mean but this is far from the truth. For example, someone stated that he uses depth jumps as being preparatory to box jumps. But if we use the definition of depth jumps as defined by the originator this statement does not hold water.
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Participant
Mortac, sorry but the book is not presently available in e-book form. I am considering doing an e version but our first have to clear my desk of a few other projects. In the interim you may be interested in some of the podcasts that I have available on my site,DoctorYessis.com.
I agree in that I don’t believe many have read my book or the one by Dr. Mann. I believe reading these books would probably answer most of the questions that have been raised.
I disagree with your conclusion that “It is difficult to argue against Mann’s conclusions as he has been employed to study the elites of USATF sprinting for the past 20+years and was an Olympic sprinter himself.” the key point here is that we are not attacking the individual — we are merely looking at some of the conclusions or statements made in lieu of other information that is available that may be contradictory or when some of the conclusions do not seem to be valid. A person’s credentials do not validate conclusions from a study or an understanding of what takes place in running. There’s no doubt that they help and play a role but in and of themselves are not valid.
The same holds true with the study by Weyand. He is considered a foremost expert on running but I strongly believe he does not understand running. because of his inability to explain his results and because his conclusions were not questioned it has led to many misinterpretations and misleading practices. The simple fact that he ignores running technique should have been a red flag for knowledgeable coaches and researchers.
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Participant
Mr. Yessis-
Can you please use the quote function. You rebut others quite a bit and it’s hard to follow your arguments the way you do it. Welcome to the forum. I love having you around. -
Participant
…When someone states a “fact” and it is questioned or someone asked for substantiation of the comment then the person who made the original statement should first substantiate that what he says is a true fact. if not, then we should just ignore what was said and move on…this is where the problem, as I see it, is. If you go back to all my posts you will see that few if any of my questions regarding the “facts” were ever responded to. Because a statement is made by a prominent author or coach does not mean that it is fact. We should be able to question anyone in regard to the statements that are made and more importantly, they should be able to back up what they say. if not, we can then assume it is only their opinion, not fact. note also that this is the basis for a valid and fruitful discussion…..
This is a very important point. Just because someone wrote it in a book or an article does not make it fact. Furthermore, it may not even rise to the level of science. There are a lot of internet warriors, some of them experienced coaches, that assume if something is discussed using scientific terminology, it is science. That’s not the case. Even references to the Russian literature, which I truly appreciate, needs to be thoughtfully considered, because much of it is opinion based on casual observation, not rigorous scientific study. That doesn’t mean it has no value, often these observations are full of extremely insightful information, but that doesn’t make it science.
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Participant
Jon, thanks for the comments and tip. I didn’t realize that this was how the quotes were done.
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Participant
star61: excellent point! something that we should all keep in mind when reading what someone else says
I must however take exception to your comments in regard to the Russian literature. I have read and translated their scientific literature as well as their coaching literature for well over 40 years. in addition, I have been to the former Soviet Union five times and have lived and worked with their coaches and professors at the coaching institutes.I also interacted with the coaches during the USSR-USA track meets and developed many close ties with them.
Because of this I believe I have a pretty good handle on what they did. believe me when I say that the caliber of their athletes was excellent as was much of their research and training that went into making the athletes. Our press however has never shown an interest to find out what they were doing. It was not secret, it was available to everyone. In fact many of my Russian journals came from bookstores in the US. in regard to those who say that their research etc. was poor, they have never been able to quote an exact study or practice to prove their point. It is a rumor that still persists to this day.
I can go on but I hope this suffices. If you like more information on this please read Secrets of Russian Sports Fitness and Training.I think it will give you a different opinion of Soviet research and training methods.
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Participant
Dr. Yessis – I’m curious if you’ve had the opportunity to read Dr. Manns “The Mechanics of Sprinting and Hurdling” (2011) or any of his other previous studies/books or have attended any of his lectures?
Obviously there are many on this forum who have followed Dr. Mann’s research and work with the USATF – so I’m curious if you, as a fellow researcher & educator, have likewise studied his work and are on equal footing with those who are quoting him.
I’m only about 90 pages into “The Mechanics of Sprinting and Hurdling” – and find his research compelling and thought provoking. As an inexperienced coach, it certainly has challenged my thinking on several topics – and has led me to question my own (limited) understanding. I’ll no doubt have to make a 2nd and 3rd pass through the book. Unfortunately, I have not yet had the opportunity to read your book.
Clearly, Dr. Mann’s has enjoyed a unique relationship with the USATF over the past 2 decades and has been privileged to have access to the USA’s elite hurdlers and sprinters for his research, as well as the latest technology to analyze their performances.
Being candid, it appears that your position on vertical force at Max V (see quotes below) is in conflict with Dr. Mann’s research and the information presented in his book.
or the most part vertical force is not crucial at MaxV. sprinters want to minimize vertical force as much as possible and generate the maximum amount of horizontal force. The higher they displace their center of mass the more wasted energy they have in order to get up higher in the air. They want the energy used to go horizontally not vertically! Gravity is a constant factor in running-there is no separate application of it
Prior to touchdown the leg should be moving backward. Thus the forces generated at contact or not vertical, they are mostly horizontal. The forces are given back via ankle extension when as you stated,the body is well in front of the foot. Thus all the forces are mostly horizontal not vertical. I explain this in great detail in the second edition of my book Explosive Running.
It’s somewhat surprising to see so many of you agreeing that the vertical component is most important in maximum speed running where the vertical displacement of the center of mass is minimal. if you rely on the vertical production of force the center of mass will be raised much higher. In essence you will then look like you were jumping up and down as you move down the track. But in world-class runners you don’t see up and down, you see what appears to be only horizontal.
It’s my understanding that Dr. Mann’s position is that at maximum velocity (MaxV) – the sum of a sprinters horizontal forces is effectively zero (0). The small amount of horizontal force (positive) at Max V is only sufficient to counter the braking (negative) action of the early part of the ground contact phase. Arguably – if the athlete was able to generate additional horizontal forces beyond the above – they would continue to accelerate and therefore wouldn’t be at maximal velocity.
So it seems Dr. Mann’s position is that nearly all the force application is vertical at Max V. He seems to have supportive data (from force platforms) and force calculations in his book (Figure 5-19 – pg 39).
Again, my understanding may be incomplete.
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Participant
I have been privelaged to review some force platform data fairly recently infact (showing the amount and direction) I have to say that at no point aprt form very briefly during the braking element was the direction of force ever below 45 degrees, which in my mind states a Vertical dominance
Would be good if we had the resourced to assess this currently following this debate, I may actually have a word with the local UNI with this in mind
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Participant
What a puzzle this is.
I’m not there yet, but I’m coming to the conclusion that over strengthening the hamstrings & quads due to how the muscle fibers run (vertically) is potentially harming speed due to a relentless pursuit of increasing air time (barbell exercises/strength).
Interesting Tyson Gay has massive glutes (horizontal fibers) but pretty skinny legs, Bolt is pretty skinny in the lower too. Couldn’t believe how skinny he looked in the flesh getting the record in Manchester (150m)
And the top verters at the combines, can’t run a decent 40, quad dominant but can’t accelerate.
Hmmmm…
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Participant
This is my understanding of the vertical forces issue: The key premise we are working with here is that at maxV, velocity remains constant. This means that there is no horizontal acceleration, and therefore the forces in the horizontal plane negate each other. Essentially, the positive horizontal acceleration applied during ground contact is equal only to the negative acceleration of braking forces during ground contact and air resistance, which are very small.
The issue of maintaining top speed is not about applying huge horizontal forces during ground contact, but minimizing breaking forces during ground contact by swinging the legs as fast as possible and minimizing ground contact time. As vertical forces applied increase, the athlete has greater vertical displacement and spends more time airborne. More time airborne means more time at that speed, and also less stride frequency is necessary to maintain top speed, reducing fatigue and allowing the legs to move faster and reduce ground contact times.
This, however, is from a purely textbook physics perspective. Of course races aren’t run on paper, athletes accelerate and decelerate small amounts throughout a run, and there are many biomechanical factors, etc., but I believe this is the reasoning behind the emphasis on vertical forces.
https://berlin.iaaf.org/news/kind=101/newsid=53084.html includes a link to a PDF (“LAVEG”) showing the instantaneous speed of Bolt in his WR run in Berlin. You can see changes of about 1.3 m/s in speed per stride, e.g. at top speed from well under 12 m/s to just over 13 m/s.
I would consider those changes not small but substantial, requiring significant horizontal forces. -
Participant
What a puzzle this is.
I’m not there yet, but I’m coming to the conclusion that over strengthening the hamstrings & quads due to how the muscle fibers run (vertically) is potentially harming speed due to a relentless pursuit of increasing air time (barbell exercises/strength).
Interesting Tyson Gay has massive glutes (horizontal fibers) but pretty skinny legs, Bolt is pretty skinny in the lower too. Couldn’t believe how skinny he looked in the flesh getting the record in Manchester (150m)
And the top verters at the combines, can’t run a decent 40, quad dominant but can’t accelerate.
Hmmmm…
Extrapolating a little there saying…..the top verters can’t run a decent 40?
A counterpoint is….all of the guys who run decent 40’s also have decent verts. Almost always.
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Participant
And the top verters at the combines, can’t run a decent 40, quad dominant but can’t accelerate.
Hmmmm…
I don’t know why you keep saying this, you have been thoroughly refuted multiple times. Multiple regression of weight and vertical produces an r of .91. Bottom line is both are related but not the same. And training to improve one will likely lead to gains in the other unless you are at a high level.
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Participant
Martijn de Lange,
https://berlin.iaaf.org/news/kind=101/newsid=53084.html includes a link to a PDF (“LAVEG”) showing the instantaneous speed of Bolt in his WR run in Berlin. You can see changes of about 1.3 m/s in speed per stride, e.g. at top speed from well under 12 m/s to just over 13 m/s.
I would consider those changes not small but substantial, requiring significant horizontal forces.Interesting – if I’m understanding this chart correctly – the graph depicts the oscillations of instantaneous speed (both positive and negative). And just as there appears to be several positive changes of >1.0 m/s – there are likewise deceleration events of a similar magnitudes.
I may be doing the math wrong…but using your 1.3 m/s, Bolt’s mass (IAAF lists him at 76) and assuming a ground contact time of .09 seconds at Max V:
Horizontal Force = 76 * (1.3/.09) = 1097 Newtons or 246 pounds
Feel free to check my math… Assuming gravity must be overcome (a vertical force) as well – his overall force budget must be quite high if these numbers are accurate.
This is 8x the average force Mann reports in his book (fig 5-19 – pg 39)
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Participant
[quote author="Alex Andre" date="1311066477"]This is my understanding of the vertical forces issue: The key premise we are working with here is that at maxV, velocity remains constant. This means that there is no horizontal acceleration, and therefore the forces in the horizontal plane negate each other. Essentially, the positive horizontal acceleration applied during ground contact is equal only to the negative acceleration of braking forces during ground contact and air resistance, which are very small.
The issue of maintaining top speed is not about applying huge horizontal forces during ground contact, but minimizing breaking forces during ground contact by swinging the legs as fast as possible and minimizing ground contact time. As vertical forces applied increase, the athlete has greater vertical displacement and spends more time airborne. More time airborne means more time at that speed, and also less stride frequency is necessary to maintain top speed, reducing fatigue and allowing the legs to move faster and reduce ground contact times.
This, however, is from a purely textbook physics perspective. Of course races aren’t run on paper, athletes accelerate and decelerate small amounts throughout a run, and there are many biomechanical factors, etc., but I believe this is the reasoning behind the emphasis on vertical forces.
https://berlin.iaaf.org/news/kind=101/newsid=53084.html includes a link to a PDF (“LAVEG”) showing the instantaneous speed of Bolt in his WR run in Berlin. You can see changes of about 1.3 m/s in speed per stride, e.g. at top speed from well under 12 m/s to just over 13 m/s.
I would consider those changes not small but substantial, requiring significant horizontal forces.[/quote]a similar study was done during the Olympics in Japan. Runners were timed at every 10 m mark. It was found that there was a speed up and a slow down in just about every segment. this also disputes the myth that velocity is constant
it should also be noted that speed during flight (while airborne) does not remain constant. Because of air resistance you slow down. The faster you go the greater is the air resistance. This is another reason for not having a high vertical projection. Taking off at a 45 a higher degree angle as someone suggested leads to slowness not greater speed.
As is well known in physics the vertical velocity of the body’s center of gravity (CG) {also known as center of mass}, at takeoff determines how high the center of gravity will travel. Since there is agreement that the CG travels no more than 1 to 3 inches in world-class runners, the vertical component must be relatively small while the horizontal component must be high. any physics or biomechanics book will substantiate this conclusion.
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Participant
What a puzzle this is.
I’m not there yet, but I’m coming to the conclusion that over strengthening the hamstrings & quads due to how the muscle fibers run (vertically) is potentially harming speed due to a relentless pursuit of increasing air time (barbell exercises/strength).
Interesting Tyson Gay has massive glutes (horizontal fibers) but pretty skinny legs, Bolt is pretty skinny in the lower too. Couldn’t believe how skinny he looked in the flesh getting the record in Manchester (150m)
And the top verters at the combines, can’t run a decent 40, quad dominant but can’t accelerate.
Hmmmm…
the vertical direction of the muscle fibers is a plus factor not a negative unless as you state you are trying to increase airtime which is the major negative. The massive glutes are a great benefit because they are activated and produce great force in the pawback action, not in the pushoff.
The glutes, hamstrings and quads change their role to absorbing and withstanding the forces on the landing. Since only the ankle joint extension is used in the pushoff and is mainly tendon involvement rather than calf muscle, muscle development need is not great. It would just make it more difficult to reposition the legs during flight. 80% of the energy used in the run is used to drive the forward and backward while 20% is expended in the ankle joint extension. (see a recent issue of science) Thus the “skinny” legs are an asset.
I explain and illustrate this in my book Explosive Running.
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Participant
Thankyou Michael.
This is what it’s all about, finding the answers, rearranging, moving forwards.
You know Carl Lewis said he never picked up a barbell & for years I had an inkling (before I even read your book) he placed massive emphasis on ankle joint extension exercises & I still suspect he paid particular attention to strengthening his feet too.
Way ahead of his time IMO.
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Participant
JC…
Not sure where you came up with this statement:
You know Carl Lewis said he never picked up a barbell & for years I had an inkling (before I even read your book) he placed massive emphasis on ankle joint extension exercises & I still suspect he paid particular attention to strengthening his feet too.
Way ahead of his time IMO.
I was always under the impression that Carl Lewis was trained my Tom Tellez. Didn’t realize he was self coached and designed his own training plans. Not sure where you gained your unique insight into Carl’s training philosophy, plans and methods.
It’s interesting that Tellez claims that Carl did indeed lift weights (although they stayed away from squats because of Carl’s back…). If you go to the Canadian Athletics Coaching Centre website – you can download an audio interview with Coach Tellez where he discusses his training philosophy as well as some of the specifics of Carl’s training.
I trust that you’ve studied Tellez’s publications and training methods with equal vigor as Dr. Yessis. Certainly Tellez’s modest coaching success with Carl, and other world class & collegiate athletes must be on par with Dr. Yessis.
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Participant
Dr. Yessis – I’m curious if you’ve had the opportunity to read Dr. Manns “The Mechanics of Sprinting and Hurdling” (2011) or any of his other previous studies/books or have attended any of his lectures?
Obviously there are many on this forum who have followed Dr. Mann’s research and work with the USATF – so I’m curious if you, as a fellow researcher & educator, have likewise studied his work and are on equal footing with those who are quoting him.
I’m only about 90 pages into “The Mechanics of Sprinting and Hurdling” – and find his research compelling and thought provoking. As an inexperienced coach, it certainly has challenged my thinking on several topics – and has led me to question my own (limited) understanding. I’ll no doubt have to make a 2nd and 3rd pass through the book. Unfortunately, I have not yet had the opportunity to read your book.
Clearly, Dr. Mann’s has enjoyed a unique relationship with the USATF over the past 2 decades and has been privileged to have access to the USA’s elite hurdlers and sprinters for his research, as well as the latest technology to analyze their performances.
Being candid, it appears that your position on vertical force at Max V (see quotes below) is in conflict with Dr. Mann’s research and the information presented in his book.
[quote]or the most part vertical force is not crucial at MaxV. sprinters want to minimize vertical force as much as possible and generate the maximum amount of horizontal force. The higher they displace their center of mass the more wasted energy they have in order to get up higher in the air. They want the energy used to go horizontally not vertically! Gravity is a constant factor in running-there is no separate application of it
Prior to touchdown the leg should be moving backward. Thus the forces generated at contact or not vertical, they are mostly horizontal. The forces are given back via ankle extension when as you stated,the body is well in front of the foot. Thus all the forces are mostly horizontal not vertical. I explain this in great detail in the second edition of my book Explosive Running.
It’s somewhat surprising to see so many of you agreeing that the vertical component is most important in maximum speed running where the vertical displacement of the center of mass is minimal. if you rely on the vertical production of force the center of mass will be raised much higher. In essence you will then look like you were jumping up and down as you move down the track. But in world-class runners you don’t see up and down, you see what appears to be only horizontal.
It’s my understanding that Dr. Mann’s position is that at maximum velocity (MaxV) – the sum of a sprinters horizontal forces is effectively zero (0). The small amount of horizontal force (positive) at Max V is only sufficient to counter the braking (negative) action of the early part of the ground contact phase. Arguably – if the athlete was able to generate additional horizontal forces beyond the above – they would continue to accelerate and therefore wouldn’t be at maximal velocity.
So it seems Dr. Mann’s position is that nearly all the force application is vertical at Max V. He seems to have supportive data (from force platforms) and force calculations in his book (Figure 5-19 – pg 39).
Again, my understanding may be incomplete.[/quote]
It is important to not confuse one’s credentials with expertise or knowledge or understanding of a particular topic. However if you wish to compare credentials look at my website- DoctorYessis.com or simply Google me.
In regard to Dr. Mann we both presented at a speed conference back in the 1980s. I have been familiar with his work for many years and do not agree with his conclusions and interpretations. Keep in mind that the research could be good but the interpretations and understanding of the findings can be erroneous. This is why I also disagreed with some of the earlier posters who stated that they were more numbers people rather than understanding what the numbers meant.
If you have been reading some of the latter posts you’ll see why the points of disagreement with the conclusions stated by Mann have been substantiated by the research. I can be wrong but it appears that he misinterpreted his initial data and it has blinded his findings in future research.
This is quite surprising especially if one were to look carefully at the film and pictures of world-class performers. Look at the pictures and film of Bolt and see if you can find a point where the vertical projection is visible. If the vertical force is the only force being exerted it should be visible. if the vertical force is somehow mysteriously converted to horizontal then how this occurs should be explained in great detail.
Even the simple fact from elementary physics should have raised a red flag. In essence it states that in order to move horizontally the forces must be projected in a horizontal direction and the vertical forces must be at a minimal. This should have been taken into consideration when the conclusions were drawn. If the conclusions did not match what was already known in science it can only mean that something was wrong with the research or his interpretation was erroneous. This necessitates going back to the drawing board.
The basis for all good research is the ability of the researcher to explain and understand the results that he receives. However when they are not capable of doing this than the research means little. The numbers may seem impressive but by themselves do not mean anything. For example as I have previously stated because there can be 1000 pounds of force at touchdown by itself is impressive but more important is what it means to the coach. How is it possible to generate this force, what actions must the runner do to generate this force,how are the forces handled by the legs at touchdown, are any of these forces given back at takeoff, which joint is mainly responsible for getting back the forces, what is the position of the body when this occurs and so on.
I answer these questions in my book Explosive Running without giving all the numbers. I am a strong believer that understanding what occurs is most important rather than memorizing numbers which are great for academic discussions but not for application on the track.
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Participant
Dr. Yessis,
Thanks for taking the time to respond to my previous post.
I think I’ll have to purchase your book to get a better understanding of your thoughts/methods 🙂
Again, I’ve not yet finished Dr. Mann’s book. I guess I’d note that he does provide data to support his conclusions. It’s my understanding that he also uses digitized computer models (using each athletes’ unique anthropometric’s and video from the USATF National Championships). I would hope that with all the technology available that changes in velocity (vertical & horizontal), height of center of mass, segment angles and velocities, would easily be measurable with these tools.
It would also seem that the underlying physics of acceleration/deceleration, bodies in motion, gravity, etc. are known and should allow a researcher to calculate the required forces, vectors, etc. for Usain Bolt or Tyson Gay to run a 100m sprint.
It would be a shame that after 20 years of critical research by Mann, as well as the other researchers employed by the USATF, that the USATF researchers don’t have a basic understanding of these fundamental concepts. Hard to believe there is no agreed upon mathematical model for human sprinting.
I’m not defending Mann – or the USATF. I’m an inexperienced HS coach – so publications such as yours and Manns are often the resources I turn to. I’m also in no position to validate Dr Mann’s research or conclusions…nor yours. That said, I’ve quickly learned to have a healthy does skepticism (being a member of Elitetrack.com mandates it)!
Again to clarify, Mann’s research does indeed show a positive horizontal force at Max V. However, it’s offset by negative forces (braking).
I look forward to reading your book…and hopefully you’ll have the opportunity to review Dr. Manns.
Thanks again.
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Participant
Refering to a previous post regarding changing speed I think someone stated that speed was measured of a sprinter and it fluctuated with each stride.
You are correct and I have seen data on this, in fact horizontal speed is diminished during ground contact and is actual ‘flight’ that creates horizontal speed.
Further, it appears that Michael direction is based on a kenieiosolgy model. As the sprinters body ‘rotates’ over the leg through a given ROM that this indicates ‘only’ horizontal force. When in fact it is the attempt or indeed application of horizontal force that slows us down.
It is the vertical force through our ROM that creates the speed at flight, as I previously posted force plate data has shown vertical force at top speed it is how this vertical forces applied is the key
And as for coaching actual athletes, I would never tell my guys to try and produce more horizontal force!!! Real life applications
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Participant
I do not recall anyone saying athletes do not need/use/require horizontal force in upright running, obviously there has to be. The disagreement, or maybe not a disagreement, is that athletes should emphasize or focus on horizontal force production when upright and close to top speed.
I have never heard any top sprint coach ever say to focus on producing horizontal force when upright. They almost all say to step over and down. Many say apply force down and get out of the way.
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Participant
So it seems Dr. Mann’s position is that nearly all the force application is vertical at Max V.
So what do athletes do to develop this vertical force application?.
Now I’m starting to fully understand why verters can’t run a 40 in the combines.
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Participant
JC here is thought for you
It’s well known that athletes/people with compliant tendons and are very flexible are very good at vert jumps and have week top end, this is due to the release of energy is over a very long period as the muscles and tendons release.
I had an athlete with hyper mobilisation who could vert 40″ without even trying but his top end was seriously bad.
We worked on his stiffness and mostly his ability to absorb and release vertical force, he took off .5 in one winter, and yes he did loose some of his vert ability
Top end is about absorbing and returning in less than .1 this becomes significant for the requirement of isometric strength and excellent tendon stiffness.
Again, as in my previous post regarding the slowing effect whilst in ground contact, compliant tendons which although great for slower energy release as in the vert are not great for absorbing and returning which allows too much sinking and then requires more muscle action which results in greater fatigue.
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Participant
The reason why net horizontal force approaches zero at top speed is because the force produced by the sprinter equals the loss of horizontal force at braking and air resistance.
Logic suggests that if a sprinter can produce greater horizontal force they will reach a higher top speed; provided force is great enough for impulse to increase as time of force production reduces. Clearly increasing vertical force will only increase vertical height (if the time of force production remains the same)…but vertical height is clearly observed to reduce to a minimal at top speed; just watch You Tube videos to confirm this.
Vertical force might be measured to increase as speeds increase simply because the time of force production decreases; in order to maintain vertical impulse (force x force production time) vertical force must increase.
Newtons laws of motion cannot be challenged here; no-one would succeed in challenging (at our low velocities relative to the speed of light)
Impulse = force x time = change in momentum = change in mass x velocity (mass is fixed)
To increase the acceleration phase of sprinting (and reach higher top velocity/speeds) the sprinter must either increase horizontal force production, reduce air resistance or decrease braking forces (technique modification perhaps); or increase force production time which is not feasible.
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Participant
It’s well known that athletes/people with [b]compliant tendons and are very flexible[/b] are very good at vert jumps and have week top end, this is due to the [b]release of energy[/b] is over a very long period as the [b]muscles and tendons release[/b].
Michael, In your book you sometimes refer to joules (J) of elastic energy in parts of the body. I just have a query regarding the amount of joules (J) of elastic energy that “could potentially” be stored in both the Achilles tendon & the arch of the foot?.
Here is a quote I took from the book: Biomechanical Basis of Human Movement, 3rd Edition. It states that both the Achilles tendon & the arch of the foot store around 54 joules (J) of elastic energy between them.
Quote: For example, the Achilles tendon can store 37 joules (J) of elastic energy, and the ligaments of the arch can store 17 J as the foot absorbs the forces and body weight.
My question is, Does an elite sprinter store more joules (J) of elastic energy than the 54 joules (J) being mentioned through training?.
And if so, What is the ‘potential estimate’ (through training) for an elite sprinter for the amount of joules (J) they store in both the Achilles tendon & the arch of the foot alone?. It’s 54 joules (J) for the average person, what about the sprinter?.
Or is the amount fixed (J) among the entire population, including athletes?.
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Participant
[quote author="COV-GOD" date="1311517443"]It’s well known that athletes/people with [b]compliant tendons and are very flexible[/b] are very good at vert jumps and have week top end, this is due to the [b]release of energy[/b] is over a very long period as the [b]muscles and tendons release[/b].
Michael, In your book you sometimes refer to joules (J) of elastic energy in parts of the body. I just have a query regarding the amount of joules (J) of elastic energy that “could potentially” be stored in both the Achilles tendon & the arch of the foot?.
Here is a quote I took from the book: Biomechanical Basis of Human Movement, 3rd Edition. It states that both the Achilles tendon & the arch of the foot store around 54 joules (J) of elastic energy between them.
Quote: For example, the Achilles tendon can store 37 joules (J) of elastic energy, and the ligaments of the arch can store 17 J as the foot absorbs the forces and body weight.
My question is, Does an elite sprinter store more joules (J) of elastic energy than the 54 joules (J) being mentioned through training?.
And if so, What is the ‘potential estimate’ (through training) for an elite sprinter for the amount of joules (J) they store in both the Achilles tendon & the arch of the foot alone?. It’s 54 joules (J) for the average person, what about the sprinter?.
Or is the amount fixed (J) among the entire population, including athletes?.[/quote]
this is a great question I believe this is where genetics may play a role together with the specific type of training being done. understand that when it comes to training many use the same terms but what actually takes place in training is very different. even a simple explanation of what takes place in a box jump — which started this discussion — will show many major differences.
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Participant
Actually is a good question.
And Michael your right the ‘terms’ used in training can refer to many different things, take box jump which seems to have got lost in the midst (I use the term as a jump from the ground up on to a box)
Does an elite sprinter have more return or just more efficient return
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Participant
I guess it would be very difficult to get my answer. You would have to separate the work done by the elastic tissues from the work done by the muscles. For the tendons to provide elastic force the contractile elements attached to the tendon will usually also be applying force. The plantar fascia would be especially difficult because there are muscles that run right along side the fascia.
For muscle tendon units, to separate the contractile work (Fxd) from the elastic work you would have to know the total length of the unit, the length of the elastic unit and the length of the muscular part of the unit over time.
Something else that fascinates me is the iliotibial band which I’m looking for ways to develop outside of sprinting/plyo’s. It’s never spoken about interestingly enough. But since it’s one huge rubber band, it may have the potential to store even more joules (J) of elastic energy than the Achilles.
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Participant
In reality, it is vertical force production that is the limiting factor in sprint performance. Attempting to artificially manipulate turnover could lead to maladaptive firing patterns of the muscles necessary for producing force at ground contact.
Again Mike, the NFL combines are telling us something very different. The guys great at going vertical are no good going horizontal.
If vertical force production was the limiting factor in sprint performance, basketball players, high jumpers or powerlifters on good sprint programs would hold the records.
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Participant
I guess it would be very difficult to get my answer. You would have to separate the work done by the elastic tissues from the work done by the muscles. For the tendons to provide elastic force the contractile elements attached to the tendon will usually also be applying force. The plantar fascia would be especially difficult because there are muscles that run right along side the fascia.
For muscle tendon units, to separate the contractile work (Fxd) from the elastic work you would have to know the total length of the unit, the length of the elastic unit and the length of the muscular part of the unit over time.
Something else that fascinates me is the iliotibial band which I’m looking for ways to develop outside of sprinting/plyo’s. It’s never spoken about interestingly enough. But since it’s one huge rubber band, it may have the potential to store even more joules (J) of elastic energy than the Achilles.
I believe you answered your own question and I agree with your comments. I would however like to point out that in studies of the Achilles tendon and calf muscle that there is very little change in the calf muscle. Most of the lengthening and shortening takes place in the Achilles tendon.
An interesting hypothesis regarding the iliotibial band but I do not believe it happens. Even if it stored energy there is no joint action that would utilize it in the takeoff.it appears to act more as a stabilizer rather than a mover
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Participant
This supports what many believe…that vertical forces are most important in early acceleration and drive phase. This is why vertical exercises, like squats and jumps, improve short sprint time but not MaxV. Which leads to the million dollar question…what exercises improve horizontal force production at MaxV (besides unresisted MaxV sprinting)?.
I found this regarding the importance of vertical force production in early acceleration and drive phase.
Original Link: https://www.ncbi.nlm.nih.gov/pubmed/19863962
“Rapid accelerations during running are crucial for the performance in a lot of sports. While high propulsive forces are beneficial to forward acceleration, vertical forces have to be small to attain high stride frequencies”.
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Participant
It is interesting to note all the statements being made about the importance of vertical forces. But yet, not one person has brought out how or what role these vertical forces play. The obvious is that they get you off the ground for the airborne phase but how much force does it take for this?
Until those who state that vertical force is most important for forward propulsion explain what they mean by this it has little meaning. Other questions that they should be able to answer are as follows:
How are the initial vertical forces generated?
What limb actions contribute to this force production?
what happens to the force after the leg makes contact with the ground? i. e. What limb and body actions take place?
How is the vertical force turned into horizontal propulsion?
How is the vertical force given back in the pushoff?
What joint action is responsible for this? In other words what joint actions take place to drive the body forward in the push-off?
Where is the center of gravity of the body when this takes place?Once these questions are answered We will have a more definitive answer as to whether vertical forces play a major role. If vertical forces are most important the people who spout these words should be able to explain and back them up.
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Participant
First…in response to JC Cooper’s previous post which just contained a portion of an abstract of a study on “accelerated running”.
It’s important to note that this study focused on acceleration (from a fly and from a standing start) – utilizing “physical education students” as subjects. So it’s relevance to previous posts regarding vertical force at Maximum Velocity may be questioned (as postures, velocities, etc. differ). And of course – these subjects were not elite sprinters (ie. Bolt, Gay, etc.).
Here is a link to the complete paper:
Body Position Determines Propulsive Forces in Accelerated Running
Dr Yessis…
Here is a link to Dr. Mann’s “The Mechanics of Sprinting and Hurdling[/url]“. I believe his research has been quoted often in this thread. It’s only $25.00 – a modest cost. I’d be interested in your review of his research and conclusions – specifically where you find errors in his methods, analysis, etc.
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Participant
We also have to keep in mind that we’re not really generating two distinct forces, veritical and horizontal, that’s just the way we mathematically define and discuss the forces. Force is being applied in many different tracectories as the body moves forward and the leg swings back. For example, the initial ground contact is primarily vertical with actually a little negative horizontal (breaking). The tracectory of the force changes, to what or when, I don’t know, but the sum of forces being applied results in a force vector at some angle, probably closer to 45 degrees than it is to vertical or horizontal, which launches the athlete on an optimal (hopefully) trajectory. From the study that I referenced earlier in this thread, which got no response, it appeared that a large vertical component, relatively speaking, was required at the earliest stages of sprinting, with the horizontal component becoming much more important as Max V is approached. What I thought was very revealing was that going from 80% to 100% Max V required very little change, about 2%, in the vertical force component, but a large relative increase in the horizontal component, about 24%.
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Participant
Star61…
Not sure if you found the full article to the abstract you referenced earlier…
Effects of running velocity on running kinetics and kinematics
Apparently this study used Australian football players on a Woodway nonmotorized force treadmill.
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Participant
In terms of sprint specific strength and power development, exercises that concentrate on force production in the horizontal directions may well lead to greater speed development, given that most exercises in the weight training room accentuate force production in the vertical plane.
^ This is probably the main reason for the differentiation between the top verts & 40yd dash times in the NFL combines.
So it seems Dr. Mann’s position is that nearly all the force application is vertical at Max V. He seems to have supportive data (from force platforms) and force calculations in his book (Figure 5-19 – pg 39).
In a way, doesn’t that ^ contradict the first quote?. Or in some way send out the wrong message?.
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Participant
RCfan2 wrote: Here is a link to Dr. Mann’s “The Mechanics of Sprinting and Hurdling[/url]“. I believe his research has been quoted often in this thread. It’s only $25.00 – a modest cost. I’d be interested in your review of his research and conclusions – specifically where you find errors in his methods, analysis, etc.[/quote]
I have a better idea. I will offer you my book, Explosive Running, for the same price and ask that you review my biomechanical and kinesiological analysis of running and the specialized strength exercises that I created to duplicate what occurs in the running stride.
If you can confirm that Mann’s book answers the questions that I posed yesterday then I will be interested in reading his book. From the excerpts and statements made during this discussion in regard to his conclusions, I see no reason to read his book. it appears that his conclusions are erroneous as they misinterpret the facts that he found.
as I stated early in this discussion any good researcher must be able to explain the results that he received. If he cannot, he must go back to the drawing board and discover what the problem is. The explanation is the most important part of any study; not the numbers that they came up with. For example, knowing that an elite runner generates up to 1000 pounds of force on touchdown by itself means little. Knowing how to generate this amount of force is however of great importance.
Picture yourself talking to a runner and telling him to generate 750 pounds of force on his landing. Is he capable of doing this? And then on the next run have him generate 850 pounds of force. Seems kind of silly isn’t it. But yet, this is what the numbers people want you to believe.
But if you told the runner exactly what to do in relation to his leg actions then he may be able to generate more force. You would also be able to determine if he has the strength to execute the action needed and if he does not be able to prescribe a specific strength exercise to duplicate this action so that he would be able to incorporate it into his running stride.
In my book Explosive Running I explained not only what happens in the running stride but also how it can be improved with the correct application of specialized strength and explosive exercises. I have two major chapters devoted to specialized strength and explosive exercises. I first learned of these exercises from Dr. Yuri Verkhoshansky on one of my trips to the former Soviet Union in the early 1980s(see the review of his latest book by Dr. Mike Young in one of his recent blogs). With my strong background in the biomechanics of sports technique I have improved on many of his exercises and developed many more specialized strength exercises for running and other sports.
It is my firm belief that if you understand what occurs in the running stride and why it occurs, you’re better able to direct the athlete to improve not only his form but also his ability to increase his speed. But you must be able to give him concrete movements in regard to what he must execute. as I learned when I was a student and as I told my students when I was a professor, “if you can’t explain it you don’t know it!”.
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Participant
Star61…
Not sure if you found the full article to the abstract you referenced earlier…
[url=https://www.fittech.com.au/downloads/treadmilldocs/Cronin_et_Effects_of_Running_Velocity_on_Running_Kinetics_8.pdf]Effects of running velocity on running kinetics and kinematics[/url]
Apparently this study used Australian football players on a Woodway nonmotorized force treadmill.
Yes, I found it. While I would have rather seen sprinters running across 60-70m of calibrated force plates, I don’t think the fact the subjects weren’t sprinters, or that they were on a treadmill, is reason enough to dismiss the study. Running mechanics on the scale we’re discussing, the major force vectors, wouldn’t be that different. The magnitude of the forces would be greater to some degree, but I see no reason why the vectors would be that different, nor the ratios of horizontal to vertical forces. Some slight differences, but not so significant that the findings shouldn’t carry some weight.
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Participant
Star61…
I don’t think the fact the subjects weren’t sprinters, or that they were on a treadmill, is reason enough to dismiss the study.
I don’t recall posting anything dismissive about this study. I only noted, as did the authors, that the study used Australian football players on a Woodway non-motorized force treadmill.
Dr. Yessis,
Sorry, I’m in no position to analyze or evaluate the works of two authors who have doctorates in their chosen fields. I have no idea whether Dr. Mann’s work is correct, nor would I be in any position to explain why his work might differ from yours. It would seem that you are in a far better position than myself to compare and contrast his work with your own.
I find it a bit disconcerting that you have been both critical and dismissive of Dr. Mann’s book – despite not showing him the courtesy of studying his work first hand. Clearly, there are many on this forum and in the US track and field community that hold Dr. Mann in some regard. I would think that out of professional respect for one’s peer – that a first hand review of his work would be warranted before you pass judgement.
I apologize to Dr. Mann for quoting his work on this post, no doubt out of context at times. I have yet to complete reading “The Mechanics of Sprinting and Hurdling” – so it was premature to make reference to it on this thread. It’s fruitless for me to try to define and defend his work.
I continue to feel it would profit everyone, including Dr. Mann, if you were to personally review his publication – to identify any errors or omissions he may have made.
Unfortunately, I have not yet had an opportunity to read your book “Explosive Running”. Although I’ve read unflattering reviews on another forum – I intend to read it with an open mind. Hopefully you’ll have the opportunity to do the same with Dr. Mann’s.
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Participant
Totally agree in order to have a ‘sound’ position it is important to review both sides
As such I have just ordered a copy of michaels book (not new though, sorry Michael) and will have a good open minded review.
I have not only read Mann’s book and many others including CF and discussed with many many elite level coaches which has shaped my views, so I will have a read and see how it provokes my reasoning.
No one can deny the range of motion the ‘foot’ is in contact with the ground however, I think what is important to consider is how much of that range is productive and positive to propulsion! And how this force is applied from a training/effort pov is more important.
I stated before and I think star has mentioned again with force plate date showing angles as low as 45 but that’s the point AS LOW AS 45
Anyway I will soon enough understand Michael view a lot better, if I agree will be seen
Will just say that although this thread is creating a huge amount of disagreement, it has definitely provoked me enough to review all my data and class notes again and just keep the mind fresh so for that I thank you Michael hope you don’t take all the ‘chat’ to heart, your input is very interesting
Oh and on a side note weynards findings and a quote of mike himself was today on yahoo uk homepage as a featured article lol
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Participant
Star61…
[quote]I don’t think the fact the subjects weren’t sprinters, or that they were on a treadmill, is reason enough to dismiss the study.
I don’t recall posting anything dismissive about this study. I only noted, as did the authors, that the study used Australian football players on a Woodway non-motorized force treadmill.[/quote]That comment wasn’t directed at you, more to those discussing this thread. While there may be other studies with better data, this study actual has vertical and horizontal forces measured on several athletes over a range of speeds. The discussions about which forces are more important in this thread have been based primarily on theory or observation. When you have empirical data, its nice to see if what’s being stated jives with the numbers.
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Participant
A huge problem with that study isn’t who is participating but rather the equipment!!!
It’s blatantly obvious that is flawed remarkable so! It’s a free rolling self repelled treadmill, obviously the faster it goes the faster the ‘casters’ move, the faster something moves the more energy/force created. Pointless test really!!!! The only way ONLY way to increase speed on those things is horizontal force
I think the only way to ever resolve this is as you pointed out. A full length straight with full spec force plates. Until someone can arrange that we are in limbo.
Though I think a huge barrier in this is most of us discuss from a ‘athlete’ or ‘coaches’ POV and others using video analysis and focus on well the ROM does this so therefore……!
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Participant
A huge problem with that study isn’t who is participating but rather the equipment!!!
It’s blatantly obvious that is flawed remarkable so! It’s a free rolling self repelled treadmill, obviously the faster it goes the faster the ‘casters’ move, the faster something moves the more energy/force created. Pointless test really!!!! The only way ONLY way to increase speed on those things is horizontal force
…..!
I’m not so sure that its so blatantly obvious. One could counter that the only way to move yourself over horizontal ground is to apply horizontal force, as Dr. Yessis has been stating. If running mechanics are not drastically different, and they’re not, I would bet the force vectors/magnitudes are fairly close to sprinting. There will be some differences, but I think you can still take something away from the fact that the differece in vertical and horizontal force when going from 80% to 100%Max V is 2% and 24% respectively.
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Participant
I look at the contact times and have to question how similar a treadmill is to true sprinting. The 100% effort group had an average of 200ms contact times: about 2.5x more than are experienced by elites in real sprinting. The increase in ground contact is going to change the feedback.
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Participant
I look at the contact times and have to question how similar a treadmill is to true sprinting.
No comparison whatsoever.
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Participant
Difference with a rolling treadmil, is that you never reach a max horizontal speed (as you would from acceleration) due to the ‘roll’
Vertical force on a free roller results in no movement, a free roller is in a state of constant acceleration hence the horizontal force is never ‘turned off’ and to get faster you must therefore apply a greater horizontal force.
This is further highlighted by the GCT as your forced to stay in contact longer in order to achive this percieved higher speed by applying a force over a longer period.
We could easily flip it the other way and use a motorised treadmill
as the accel phase is taken control of (just as the use of acceleration) then if you want to run on it as fast as possible without being thrown off, what do you do?
You apply vertical force, fast! because if you try and apply horizontal through a full ROM (deliberate ext trying to push all the way through as being suggested!) you cant apply power and speed through it and you vanish into the wall or the cute fitness instructer behind you.
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Participant
I have a better idea. I will offer you my book, Explosive Running, for the same price and ask that you review my biomechanical and kinesiological analysis of running and the specialized strength exercises that I created to duplicate what occurs in the running stride.
If you can confirm that Mann’s book answers the questions that I posed yesterday then I will be interested in reading his book. From the excerpts and statements made during this discussion in regard to his conclusions, I see no reason to read his book. it appears that his conclusions are erroneous as they misinterpret the facts that he found.
as I stated early in this discussion any good researcher must be able to explain the results that he received. If he cannot, he must go back to the drawing board and discover what the problem is. The explanation is the most important part of any study; not the numbers that they came up with. For example, knowing that an elite runner generates up to 1000 pounds of force on touchdown by itself means little. Knowing how to generate this amount of force is however of great importance.
Picture yourself talking to a runner and telling him to generate 750 pounds of force on his landing. Is he capable of doing this? And then on the next run have him generate 850 pounds of force. Seems kind of silly isn’t it. But yet, this is what the numbers people want you to believe.
But if you told the runner exactly what to do in relation to his leg actions then he may be able to generate more force. You would also be able to determine if he has the strength to execute the action needed and if he does not be able to prescribe a specific strength exercise to duplicate this action so that he would be able to incorporate it into his running stride.
In my book Explosive Running I explained not only what happens in the running stride but also how it can be improved with the correct application of specialized strength and explosive exercises. I have two major chapters devoted to specialized strength and explosive exercises. I first learned of these exercises from Dr. Yuri Verkhoshansky on one of my trips to the former Soviet Union in the early 1980s(see the review of his latest book by Dr. Mike Young in one of his recent blogs). With my strong background in the biomechanics of sports technique I have improved on many of his exercises and developed many more specialized strength exercises for running and other sports.
It is my firm belief that if you understand what occurs in the running stride and why it occurs, you’re better able to direct the athlete to improve not only his form but also his ability to increase his speed. But you must be able to give him concrete movements in regard to what he must execute. as I learned when I was a student and as I told my students when I was a professor, “if you can’t explain it you don’t know it!”.
I will buy you Mann’s book or send you my copy if you would be willing to read it and comment on it.
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Participant
I look at the contact times and have to question how similar a treadmill is to true sprinting. The 100% effort group had an average of 200ms contact times: about 2.5x more than are experienced by elites in real sprinting. The increase in ground contact is going to change the feedback.
Interesting point. What kind of GCT would you expect out of these athletes on a track?
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Participant
Difference with a rolling treadmil, is that you never reach a max horizontal speed (as you would from acceleration) due to the ‘roll’
So you can run a hundred miles an hour on this treadmill? I think that’s way off…I bet the max speed is LESS than you could generate on a track.
Vertical force on a free roller results in no movement, a free roller is in a state of constant acceleration hence the horizontal force is never ‘turned off’ and to get faster you must therefore apply a greater horizontal force.
This makes no sense. Vertical force only on a track also results in no net movement. Its called jumping in place. Most of what you’re saying is just rambling psuedo observation. There are diffences on the treadmill. A longer GCT is appears to be one. But nothing your saying makes any sense.
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Participant
I appreciate your requests to have me read Dr. Mann’s book. I do not care to read it for several reasons that have nothing to do with Dr. Mann — who I met at a speed conference over 30 years ago. At that time I disagreed with his position On the role of the ankle in sprinting in spite of what is well known in physics and biomechanics.
Many of you have indicated his position on the role of ground reaction forces. I am in accord with his findings that vertical force production is great on initial touchdown and is a key factor in sprinting. However I am not in agreement with his interpretation of his own data which is contrary to what is well known in physics and biomechanics. For example, it is well accepted that if you wish to move an object horizontally you must apply a horizontal force. This is elementary but yet we are led to believe that it is the vertical force that moves you horizontally.
It appears Dr. Mann is in agreement with Dr. Weyand (who is considered to be one of the top experts in running) who also concluded that greater ground reaction forces are the key to running speed. There is no doubting or questioning of the data that was found in their studies. They are all very legitimate studies.
However, and this is most important as I have mentioned several times previously,the true value of any study lies in how the data is explained and interpreted. This is where I am in disagreement. In none of the studies was how the vertical forces were generated explained nor what happened to the forces after the foot was in contact with the ground explained or where the body was when the force was given back. There are other points that can be shown to be erroneous but these should suffice.
Because I do not have much free time at present I must prioritize what I do. Reading a book which I already know has misinterpretations is not my idea of valuable use of my time. If you wish me to comment on any particular conclusions or recommendations that he has drawn I would be happy to do so.
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Participant
Dr. Yessis…
I probably should just let this go…and this is just my understanding of what I’ve read (disclaimer). I’m going to number my points – so that you can indicate where you agree or disagree
My previous posts were specifically in regards to forces at maximum velocity (Max V).
1) I hope we can agree that at Max V. the athlete is no longer accelerating.
2) Likewise – I hope we can agree that at Max V. – ground contact times are at their shortest.
3) And as ground contact times decrease – the athlete has less time to apply force to the ground moving underneath them.
4) Force has magnitude, duration and a vector – so when horizontal force or vertical force is mentioned – its an effective force in a given direction (ie. if a force is applied at 45 degrees – it has both vertical and horizontal components).
5) It safe to say that the athlete is not able to apply a pure vertical nor pure horizontal force while running at maximum velocity.
6) And if the athlete is no longer able to accelerate and has reached Max V – then the applied “positive” horizontal forces would have to be equal in magnitude to the “negative” horizontal forces encountered (braking action, wind resistance, friction, etc.) – else the athlete would either continue accelerating or begin to decelerate.
This would appear to be consistent with Newton’s laws of motion.
7) Dr. Mann does not exclude horizontal forces at maximum velocity and at no point does he indicate that vertical forces create horizontal motion – he’s only stating that there is no change in effective horizontal force at Max V.
8) He includes force platform traces indicating both positive (accelerating) and negative horizontal forces (deceleration) found during the ground contact phase.
9) The mass of an athlete remains constant during a sprint
10) That if the mass of the athlete is known, and the duration of the ground contact is known, then the amount of force required for a given change the velocity can be calculated:
Force = mass * change in velocity / ground time
11) And if that force is in a vertical direction – then the amount of applied force must also take into account the effect gravity has in resisting the upward movement of a given mass.
Force = (mass * change in velocity / ground time) + athletes mass
I’ll stop here to see where you might agree or disagree.
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Participant
Star come on!! lol my comments are defo not psuedo and you should really understand what I said, their fairly basic,
As for the 100mph comments that would be expected from JC lol the point being that you always have to accelerate the roller.
This is basic physics, rcfan2 is getting a very good grasp from reading Manns book
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Participant
Star come on!! lol my comments are defo not psuedo and you should really understand what I said, their fairly basic,
As for the 100mph comments that would be expected from JC lol the point being that you always have to accelerate the roller.
You said,
The only way ONLY way to increase speed on those things is horizontal force.
I believe that, and I believe the only way to increase horizontal speed on the ground is to increase horizontal force.
Not saying it doesn’t have to be accompanied by vertical force, but are you actually saying that sprinting over ground does not have a horizontal force component?Difference with a rolling treadmil, is that you never reach a max horizontal speed (as you would from acceleration) due to the ‘roll’
You said this, not me. If you don’t reach a max horizontal speed, then do you accelerate to infinity…no. My point with the 100mph statement, is that it IS ridiculous because there IS a max horizontal speed that each athlete can reach.
Vertical force on a free roller results in no movement, a free roller is in a state of constant acceleration hence the horizontal force is never ‘turned off’ and to get faster you must therefore apply a greater horizontal force.
Again, vertical force in the absence of horizontal force results in no horizontal displacement whether you’re on a treadmill or the track. A free roller is no different from a running athlete in that there is momentum, and ALL the horizontal force comes from the athlete in both cases. And you now contradict yourself by saying the only way to go faster is to increase horizontal force.
You apply vertical force, fast! because if you try and apply horizontal through a full ROM (deliberate ext trying to push all the way through as being suggested!) you cant apply power and speed through it and you vanish into the wall or the cute fitness instructer behind you.
This is baseless commentary because you have no idea what the vertical and horizontal forces are, and what increasing one or the other might do.
The only real way to discuss the forces is to actually measure them during a sprint. I have presented data from a treadmill study, flawed as it might be, but I see no other data presented concerning the vertical and horizontal forces which were measured at various speeds, including Max V. Post those and we can discuss the differences. In fact, if you have valid force measurements from a free sprint, we can discuss those. But let’s talk about the data, not about what you think might be going on by observation.
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Participant
Dr. Yessis…
I probably should just let this go…and this is just my understanding of what I’ve read (disclaimer). I’m going to number my points – so that you can indicate where you agree or disagree
My previous posts were specifically in regards to forces at maximum velocity (Max V).
1) I hope we can agree that at Max V. the athlete is no longer accelerating.
A) At Max V the athlete accelerates and decelerates over the distance. This was brought out previously and substantiated by several studies.
2) Likewise – I hope we can agree that at Max V. – ground contact times are at their shortest.
A) agree3) And as ground contact times decrease – the athlete has less time to apply force to the ground moving underneath them.
A) Disagree. The athlete exerts the force in less time.
4) Force has magnitude, duration and a vector – so when horizontal force or vertical force is mentioned – its an effective force in a given direction (ie. if a force is applied at 45 degrees – it has both vertical and horizontal components).
A) Agree
5) It safe to say that the athlete is not able to apply a pure vertical nor pure horizontal force while running at maximum velocity.
A) Agree
6) And if the athlete is no longer able to accelerate and has reached Max V – then the applied “positive” horizontal forces would have to be equal in magnitude to the “negative” horizontal forces encountered (braking action, wind resistance, friction, etc.) – else the athlete would either continue accelerating or begin to decelerate.
A) Agree — see above
This would appear to be consistent with Newton’s laws of motion.
7) Dr. Mann does not exclude horizontal forces at maximum velocity and at no point does he indicate that vertical forces create horizontal motion – he’s only stating that there is no change in effective horizontal force at Max V.
A) But there is
8) He includes force platform traces indicating both positive (accelerating) and negative horizontal forces (deceleration) found during the ground contact phase.
A) Agree.
9) The mass of an athlete remains constant during a sprint
A) Agree
10) That if the mass of the athlete is known, and the duration of the ground contact is known, then the amount of force required for a given change the velocity can be calculated:
Force = mass * change in velocity / ground time
A) Disagree F = M x a ground time only applies when dealing with power
11) And if that force is in a vertical direction – then the amount of applied force must also take into account the effect gravity has in resisting the upward movement of a given mass.
A disagree — mainly because gravity is a constant factor
Force = (mass * change in velocity / ground time) + athletes mass
it is now time to let this thread go. Instead of getting bogged down on the “science” I would like to see everyone respond to some of the questions I posed earlier. They deal with the practical application of this knowledge. We must be able to apply the knowledge if it is to be of any value to a coach. Thus when we talk about landing forces it is important to know how they are created. For example, what are the joint actions and limb movements that occur to produce this great force on touchdown? This is where I wish you would all read my book Explosive Running as its main focus is on the practical application of the knowledge. once we know the actions that occur we can then prescribe specialized strength exercises to improve and enhance the movements. To me this is the most important thing that a coach can do to improve his runners performance.
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Participant
[it is now time to let this thread go. Instead of getting bogged down on the “science” I would like to see everyone respond to some of the questions I posed earlier. They deal with the practical application of this knowledge. We must be able to apply the knowledge if it is to be of any value to a coach. Thus when we talk about landing forces it is important to know how they are created. For example, what are the joint actions and limb movements that occur to produce this great force on touchdown? This is where I wish you would all read my book Explosive Running as its main focus is on the practical application of the knowledge. once we know the actions that occur we can then prescribe specialized strength exercises to improve and enhance the movements. To me this is the most important thing that a coach can do to improve his runners performance.
Dr. Yessis, while I think I lean toward your assertions that there must be horizontal forces for horizontal motion to take place, I don’t think the science regarding the vectors and magnitudes of these forces has been resolved, at least I have not seen in this thread any studies that have measured, empirically, the forces vectors involved in sprinting, other than the treadmill data I referred to. Are you aware of actual force vector measurements? If not, then I’m not sure the knowledge you’re referring to can be accepted as scientific fact, but would rather be scientific inference, which is something a little different. Can we at least review all the literature available to reach some type of concensus on what the forces are and in what vectors they are being applied?
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Participant
Dr Yessis…
I appreciate you taking the time to reply.
Having completed my first pass through Dr. Mann’s book today, I hope to have a chance to read your book in the near future.
Your thoughts and comments are appreciated…and hopefully I’ll enjoy a better understanding of your training philosophy after I’ve read your book.
Thanks again…
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Participant
Nobody has yet recommended any exercises which optimally develops horizontal force?. That I’m sure will remain the case, lol.
I think a lot of horizontal force development has a lot do with the arms (resilience/endurance/power) in running/sprinting Vs how you use the arms in jumping/dunking.
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Participant
Mel Siff in his legendary book Supertraining on Directional Specificity.
“In some events, such as swimming, inertia plays a major role in the entire process, unlike in running, where the specificity of movement depends on horizontal thrust and the vertical oscillation of the athlete’s center of gravity.”[i]
“To fulfill the criteria of correspondence with respect to the amplitude and direction of movement, it is advisable to select the exact starting position and posture of the athlete, as well as to calculate the direction of action of the forces associated with the working links of the system and the additional load. The line of action of the applied external resistance and of the loaded movement as a whole must also be taken into account.”
“For example, in middle-distance running, skiing and skating, a knapsack full of sand or a weight belt are sometimes used as resistance. However, the muscles which bear the load are those which resist the weight of the body. This can increase the ability to cope with vertical loading and develop general strength-endurance, but does not strengthen those muscles which propel the body horizontally.”
“Similarly, a skater may execute jumps on one leg on the floor or from a bench. These exercises strengthen the leg muscles supporting the body and the static-endurance of the back muscles, but do not fully imitate the working of the muscles for the push-off, where the force is directed backward.”
“Skaters should use another method or resisted movement by changing the direction in which the force of resistance is acting. [Figure showing three different towing methods; 1) towing a human, 2) towing a weighted sled, and 3) towing a sled with a human sitting on it while skating] These methods to a large extent match the training exercise to the dynamics of the sport specific actions.”[ii]
“The strength exercise should not only reproduce the full amplitude of the movement but also the specific direction of resistance to the pull of the muscles.”[iii]
Siff then explains how sport typically involves simultaneous coordinated tension of muscle groups, such as the simultaneous flexion and extension at the two hip joints in running, where the angular movement of one leg enhances the push-off movement of the other. [He depicts the following exercises, which he credits to Verkhoshansky in 1977, to illustrate complex exercises for simultaneous strengthening of the hip flexors and extensors, and knee extensors.][iv]
Siff, Mel. Supertraining. 5th Ed. Supertraining Institute, 2003: 138.
[ii] Siff, Mel. Supertraining. 5th Ed. Supertraining Institute, 2003: 241-242.
[iii] Siff, Mel. Supertraining. 5th Ed. Supertraining Institute, 2003: 244.
[iv] Siff, Mel. Supertraining. 5th Ed. Supertraining Institute, 2003: 242.
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Participant
Nobody has yet recommended any exercises which optimally develops horizontal force?. That I’m sure will remain the case, lol.
I think a lot of horizontal force development has a lot do with the arms (resilience/endurance/power) in running/sprinting Vs how you use the arms in jumping/dunking.
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Participant
” date=”1312403714″][quote author="JC Cooper" date="1312378849"]Nobody has yet recommended any exercises which optimally develops horizontal force?. That I’m sure will remain the case, lol.
I think a lot of horizontal force development has a lot do with the arms (resilience/endurance/power) in running/sprinting Vs how you use the arms in jumping/dunking.
https://www.powersprint.space2u.com/Engelsk.html%5B/quote%5D
Do you have the book Ashley?.
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Participant
the vertical direction of the muscle fibers is a plus factor not a negative [b]unless as you state you are trying to increase airtime which is the major negative.[/b]
Would increasing airtime be a major negative if you had a +2.0 m/s tailwind in a 100m race in your view?.
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