YES, NO, MAYBEE SO, WHY OR WHY NOT?
Increased Hip Height=Greater Airtime=FASTER TIMES?
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Participant
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ParticipantRiddle me this batman….
Does hip height increase speed?
Does speed increase power?
Does power increase hip height?
I addressed this in another forum and have no answer.
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KeymasterI'm not Batman but here are my thoughts on the topic anyhow:
- [*]Increased hip height should increase flight time because increased hip height is associated with toe off occuring close to directly under the location of the center of mass. [*]A toe off from this location would in theory produce greater vertical forces at the moment of toe off which are associated with a higher max velocity. The greater airtime (and also speed) is a result of the increased vertical forces and not directly the cause of it.
ELITETRACK Founder
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Participant
Right, so from what Mike has said it sounds like speed will increase hip height, but as we know trying to increase hip height will not make you faster. So more power=more speed=higher hip height or more speed=more power=higher hip height.
I don't think higher hip height=more speed=more power because if you're skipping as high for height you're going to get higher hip height, but obviously not better speed than sprinting -
Keymaster
Pete,
I think you might have misunderstood me, I tried to say the following:Increased hip height is an indication that toe off is occuring relatively close to being directly under the center of mass (BDC: bottom dead center). When toe off occurs close to BDC vertical force application will be greater due to the fact that force is being applied under the center of mass rather than behind it (which would produce less vertical forces and greater horizontal forces). Increased vertical force application is associated with greater max velocity. Consequently, "high hips" is most likely an indicator of efficient sprint mechanics.
Check out the picture I've drawn to help clarify. These two stickmen and all their segments are of exactly equal size. This demonstrates how toe off position affects hip height as well as the force vectoor. Hopefully, it's true what they say about pictures equalling a thousand words.
ELITETRACK Founder
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Participant
What methods are used to improve hip height that are technique based? Is this something that it obtained by power or can you do specific drills to integrate this into your running style.?
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Keymaster
2belite-
You're very very correct on that. The pictures are a little exagerated to get the point across. In the real world, a "high hips" sprinter would probably look more like the "low hips" stickman, with the "high hips" stickman being a near impossibility for a real athlete.ELITETRACK Founder
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Participant
my coach always told me that you wanted to have a higher hip position as so not to waste so much energy trying to raise your center of mass up each step. You use less energy to keep your COM up, and then you can use that energy to counteract the deceleration in the latter stages of your race….
but what do i know? not much… -
Keymaster
JJ & Tank,
Good points guys! You guys are not only pointing out the same thing but I think it's a part of the equation I left out. In a spring-mass (or elastic) system, energy in roughly equals energy out and thus less intrinsically created (muscle) force is needed to be produced by the athlete (ala Tank's wasted energy). Consequently, JJ's, "increase the stiffness of the spring" = Tank's "You use less energy to keep your COM up, and then you can use that energy to counteract the deceleration in the latter stages of your race."I left this part of the equation out because I kind of think it's somewhat a result of the what I posted above but it can indeed become a chicken or egg situation. That is:
[*]The above technical recomendations lead to–> greater vertical force application at toeoff[*]More vertical force application at toe off–> greater vertical displacement of mass (higher flight phase)[*]Greater vertical displacement of mass (higher flight phase)–> greater loading of support leg at touchdown (greater force in) [*]If there is greater force in and IF the spring is stiff, the greater force in = greater force out at less energy expense.[*]Greater force out at less energy expense = less deceleration.
ELITETRACK Founder
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Keymaster
I'd like to add that horizontal force application (and more specifically impulse) cannot be ignored as it is still THE force / impulse that keeps the body moving forward and is what counters the air resistance force and initial braking forces at ground contact.
Increased vertical force / impulse just affords the sprinter enough flight time to keep moving forward fast (time in flight is probably more efficient than time on the ground because initial braking forces are so costly to velocity and cause such marked deceleration) and also helps to reload the leg to a greater magnitude at ground contact because the increased height of the flight phase equals increased vertical ground reaction forces at touchdown.
ELITETRACK Founder
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Participant
this is the paradox
what's the trade-off?
1) to train these qualities you need to be going fairly fast, which by it's nature requires long recoveries and allows very few runs… so you almost have to train the power needed for the run seperately and the do what you can to give the athlete some feel (even if it's fake) of what it will be like when they do it right **before they can do it. to me this is one of the values of testing and competetive practices — you get to see what qualities are "stable" under pressure.
2) tempo runs and runs at 90% won;t allow you to achieve certain technical feautres… so even though i don't want tempo runs and speed endurance runs to be sloppy there are certain thing that you have to "let go" per se because the power requirement is too big to survive the workout…
where do you compromise?
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Keymaster
I don't have an answer but it brings to mind this great but forgotten thread < https://elitetrack.com/messageboard/viewthread.php?tid=107 >.
Also KT, you mentioned creating a "fake" feel. How do you fake the feeling of doing the technical aspects correctly without the force needed to do it correctly…..assisted runs maybe?
ELITETRACK Founder
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Participant
[i]Originally posted by mike[/i]
Also KT, you mentioned creating a "fake" feel. How do you fake the feeling of doing the technical aspects correctly without the force needed to do it correctly…..assisted runs maybe?hmm…. i know Charlie says assisted runs pulls the CM forward into the ground thereby reducing hip height… but i even meant drills or even "fast straight leg bounding" (maybe even assisted) where you're feeling the hip position and a reduced backside push… so the emphasis would be on a "hot track" or reduced horizontal push. these can also be fdone with a small wt vest (3-10% bw) as a means of special strength training.
as i've alluded to before, i like to contrast this type of work with real sprinting, e.g., 10-20m flying sprints.
So I might do:
2-3 x 15m straight leg bound (10-25m run in)2 x 15m flying sprint (w/20-40m run in)
during the bounds you can cue as above and then tell the athlete that you want them to have the same feel in sprinting.my 02.
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Participant
Are there any sprinting cues to improve this action when sprinting. I've already heard of the toe up-heel up-knee up cue, but this action just seems to keep the athlete lower to the ground (low hip height)
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Keymaster
Whether an assisted run pulls a person down to the ground is mostly a result of where the line of pull is in relation to the person's center of mass. If it is above the COM (as in a pulley from a slightly elevated position) then this might create the "fake" feeling we're discussing. If the pull is in line with the sprinter's COM (as is ussually the case) or even worse, below it, then the sprinter will be pulled into the ground as Charlie has said.
As for cues, I like "run tall," "push yourself up," "feel bouncy" and "high hips" These are simple cues that have worked well for me.
ELITETRACK Founder
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Keymaster
Several people have asked for the picture that was originally attached to one of my earlier messages in this thread but was deleted when I upgraded the messageboard software. I thought the picture was gone forever but I found the picture on an old computer this weekend so here it is…..
ELITETRACK Founder
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Participant
thats not the original picture! mike dont act like youre good at drawing! 😀
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Participant
Can you briefly explain the picture and say what bfd stands for?
thanks. -
Keymaster
The picture (which is the original pic) was intended to show the effect of toe off position on the force application vector. In a nutshell, higher hip height is often indicative of a toe off position which is closer to BDC (bottom dead center….as in cycle crank position) which is associated with more vertical force application and higher top end running speeds.
ELITETRACK Founder
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Keymaster
[i]Originally posted by senri[/i]
won’t this minimize turnover by having high hips or try to get the bouncy feeling half way through the 100m?I’ve never noticed this to be the case. And besides, turnover is only one component of speed. Any cost to turnover that high hips might cause (I’ve never noticed any) would more than be made up by increased stride lengths via better ground contact position and more efficient force application.
ELITETRACK Founder
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Participant
i ask cause to get the bouncy feeling i try to bound and i go fast (my coach says) but i feel slow, with running turnover it gives me that psychological aspect. But technique wise thats my biggest problem which is getting the best out of my stride, and putting less emphasis on turnover, i can’t yet atleast get the bouncy feeling and go fast fast. I feel like i’m grazing the ground and am goin nowhere. When i do put emphasis i extend to the max when im around the 40-50m mark i feel slow though. Basically i’m trying to figure out how to associate the turnover with the stride, but my stride is not coming through….Ah yes patience with everything :bounce:
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Keymaster
You are what I call a “turnover addict.” You mistakenly associate limb speed (i.e. turnover) with moving fast without realizing that their are other factors which come into play. The slow feeling you get when you run “bouncy” is pretty normal for turnover addicts who start to run correctly. The reason you get this sensation is because your flight times and distances are longer as a consequence of increased vertical force application at ground contact. Ignore your gut instinct and trust that you are running faster. When the correct running mechanics become natural you should really see some improvements.
ELITETRACK Founder
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Participant
I reread this thread before I did my workout today, and it kept churning in there until this was the final result.
I was thinking about how inefficient training top speed was for the reasons KT mentioned: the need for long recoveries. Also I read the thread on the best distance for top speed development and the majority of the acceleration seems like wasted energy to me and creates the need for those long recoveries.
Now KT mentioned using straight leg bounding as one method of special strength training for MaxV. Would the example Mike gave in a different thread of using stadium stairs (for height to mimic top speed mech) be another way? My question is where is the line drawn for how much is used in a session and in how many sessions in the micro.
So my thoughts are here right now. Say I have 8 weeks of MaxV broken into two 4 week micros, with three weeks of full vol followed by a one week unload period. Speed is done 3 days a week. Would I be best setting it up like this? For the first micro I would have roughly half of the vol come from the track (ie flying 20’s) and half come from the drills like KT mentioned. For the second micro I would do roughly 75% on the track and 25% drills, so that I can adapt fully to running at MaxV but still I am keeping the drills in there to maintain the gains from them from the previous micro?
Does that sound like it would work, or am I better off sticking with flying 20’s?
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Keymaster
Now KT mentioned using straight leg bounding as one method of special strength training for MaxV. Would the example Mike gave in a different thread of using stadium stairs (for height to mimic top speed mech) be another way? My question is where is the line drawn for how much is used in a session and in how many sessions in the micro.
I personally don’t like to use simulated MaxV work more than 1x / week for a couple weeks.
So my thoughts are here right now. Say I have 8 weeks of MaxV broken into two 4 week micros, with three weeks of full vol followed by a one week unload period. Speed is done 3 days a week. Would I be best setting it up like this? For the first micro I would have roughly half of the vol come from the track (ie flying 20’s) and half come from the drills like KT mentioned. For the second micro I would do roughly 75% on the track and 25% drills, so that I can adapt fully to running at MaxV but still I am keeping the drills in there to maintain the gains from them from the previous micro?
Does that sound like it would work, or am I better off sticking with flying 20’s?
I think that could work. I don’t think it would be quite as beneficial as the flying 20s though. What event are you doing this for?
ELITETRACK Founder
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Participant
My opinion is that top speed improvement is one of those things you kinda have to just let happen. It seems to be more of a product of stability/strength/posture mixed with freedom of movement. I don’t know how much you can force it along with plain flying runs and drills (not a big fan of drills other than for warmup).
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Participant
I run everything from the 55 through the 400, with the 200 being my preferred race. I do the majority of my speed work in the offseason because inseason is spent mostly prepping for the high load done at the conference meet (up to 6 races in 2 days. Two 55’s, three 200’s and a 400) and speed work is done about once a week, up to twice a week late in the season.
Basically I was wondering if I would be able to do the drills to increase the amount of foot contacts per session without burning out or losing quality, so at the end of the macro I would have done X amount more speed work than say by doing flying 20’s alone.
It was a long shot, but hey it popped in my mind and I figured I’d ask.
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Participant
I run everything from the 55 through the 400, with the 200 being my preferred race. I do the majority of my speed work in the offseason because inseason is spent mostly prepping for the high load done at the conference meet (up to 6 races in 2 days. Two 55’s, three 200’s and a 400) and speed work is done about once a week, up to twice a week late in the season.
Basically I was wondering if I would be able to do the drills to increase the amount of foot contacts per session without burning out or losing quality, so at the end of the macro I would have done X amount more speed work than say by doing flying 20’s alone.
It was a long shot, but hey it popped in my mind and I figured I’d ask.
I am aware. If I were you I would be most concerned about not getting sick or injured. It is unfortunate that you have to spend so much time prepping for running too many events at the conference meet. Sadly this is often the case. I’d rather see you run 10.50 than successfully run 4-5 events but most people(coaches) are worried about squeezing out points rather than ultimate performance.
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Keymaster
I’ve found that you can substitute well for acceleration work and for tempo work but anything in between (maxV and speed endurance) is MUCH harder to find an acceptable substitute. You really just gotta do it if you want to get better.
The reason I asked which event is because if you were a short sprinter, which you are, then I don’t think you should look at the build up to maxV as being inefficient or a waste of energy. In fact, I think 60m-80m sprints are often the glue that solidifies performance for short sprinters. It touches on all the elements you would in a competition (acceleration, maxV, short speed endurance) and although you can’t do too much of it it’s very important to look at the big picture and not focus on one element because in the grand scheme of things all of those components are dependent on each other.
ELITETRACK Founder
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Participant
Mort- Yeah, it isn’t the most ideal situation but the sprinters on our team score roughly 75% of our points with the rest coming from the field, so the head coach puts a lot of pressure on the sprint coach to make us perform well in everything possible. At least my sprint coach realizes its not ideal either, but there isn’t a lot that can be done with our small team (which thankfully added some more talent this year).
Mike- Thanks, that makes a lot of sense.
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