Why Do Sprint Work ?? OR The Myotatic Reflex Needs Training !!

[Michael Ro]

This article showing that human runners reach faster top
speeds, not by repositioning their limbs more rapidly in the
air, but by applying greater support forces to the ground
should be of interest to coaches and athletes on this group:

Weyand PG, Sternlight DB, Bellizzi M & Wright S Faster
top running speeds are achieved with greater ground
forces not more rapid leg movements. J Appl Physiol 2000
Nov; 89(5): 1991-9

We twice tested the hypothesis that top running speeds are
determined by the amount of force applied to the ground rather
than how rapidly limbs are repositioned in the air.

First, we compared the mechanics of 33 subjects of different
sprinting abilities running at their top speeds on a level
treadmill. Second, we compared the mechanics of declined (-6
degrees) and inclined (+9 degrees) top-speed treadmill running
in five subjects. For both tests, we used a treadmill-mounted
force plate to measure the time between stance periods of the
same foot (swing time, t(sw)) and the force applied to the
running surface at top speed. To obtain the force relevant for
speed, the force applied normal to the ground was divided by
the weight of the body (W(b)) and averaged over the period of
foot-ground contact (F(avge)/W(b)). The top speeds of the 33
subjects who completed the level treadmill protocol spanned a
1. 8-fold range from 6.2 to 11.1 m/s. Among these subjects,
the regression of F(avge)/W(b) on top speed indicated that
this force was
1.26 times greater for a runner with a top speed of 11.1
vs. 6.2 m/s.

In contrast, the time taken to swing the limb into position
for the next step (t(sw)) did not vary. Declined and inclined
top speeds differed by 1.4-fold (9.96 vs. 7.10 m/s,
respectively), with the faster declined top speeds being
achieved with mass-specific support forces that were 1.3 times
greater (2.30 vs. 1.76 F(avge)/ W(b)) and minimum t(sw) that
were similar (+8%).

We conclude that human runners reach faster top speeds not by
repositioning their limbs more rapidly in the air, but by
applying greater support forces.

[Eduardo Su]

Interesting. Here is a link to the abstract:
http://www.uth.tmc.edu/apstracts/2000/jap/September/438a.html

So basically, this is saying, don't elongate your stride and
don't increase your turn-over to achieve greater speed. For
instance, at
http://www.fasterthangravity.com/Speedquesanspg.htm we read:

"The drills we do to improve top end speed are not really
accomplishing what we think they are. Step frequencies and
contact lengths are NOT the secret to top speed.

"How do we know this? The range of stride frequency between
runners at various speeds is actually narrow. There is little
variation in step frequency Also, contact length at
intermediate and highs speeds does not vary all that much
between runners either."

Now, how do we explain that mid to long-distance world class
runners seem to settle at a turnover rate of about 180
steps/minute, while their sprinting, short-distance
counterparts implement a higher turnover? The force findings
aren't exactly surprising, btw. Compare the legs of a 100
meter sprinter with those of a 5K runner and you will have
little doubt as to who is exerting the greatest force on
terra firma.

From my own personal experience, I gain speed not by reaching
forward (elongating my stride) or by increasing turnover rate,
but by pushing back on the road with increased . . . you
guessed it, force. Using Ozzie's analogy, he would say to
increase speed by increasing the forward lean, then catching
yourself; and this, too, is a force equation, because the
"catch" is halting the force of gravity. BTW, Ozzie's "catch
yourself as you fall forward" picture seems to fit this
research quite well. Also in <>, we read:

"Why do we have so many problems with this?

"The problem is the way we analyze maximum velocity mechanics.
We imagine propulsion, when there really isn't any. We believe
the secret is in horizontal velocity, when, in actuality, peak
vertical ground reaction forces are 5 to 10 times greater than
peak horizontal forces.

"Is this some kind of paradox?

"Not really-think of it this way: If we run at a constant
speed against no air resistance, the forces that increase
forward velocity before take-off simply offset the breaking
forces that decrease the body's velocity on landing. Thus,
they 'cancel each other out.' As a result, we can say that the
net horizontal forces at steady speed running are
really...zero. Horizontal force does NOT explain the
differences in top speed. This is exactly what the
contemporary research makes clear. We can challenge this by
arguing that treadmill testing (standard for human locomotion
research) does not duplicate the demands of actual sprinting,
yet even if we were to compare the way athletes sprint uphill
or downhill, or if we were to change the characteristics of
the running surface, the basic mechanical variables are not
affected."

Of course, the phrase "at steady speed" conveniently
oversimplifies. Sprinters--and other runners, for that
matter--must *accelerate* in the horizontal plane to go from
one speed to another (from 0 to top running speed), and
mass(your weight)*acceleration = FORCE. Add to this that
runners do not run in a frictionless/lossless, environment,
and horizontal force of some sort must be applied to produce
forward motion.

--
Eduardo Suastegui "Test everything. Hold on to the good."
(remove '701' when replying via e-mail)

"Michael Roose" <trainerofathletes@email.com> wrote in message
news:ouv5juk80uk0n7rl61t99bn4eq36763gmh@4ax.com...
> This article showing that human runners reach faster top
> speeds, not by repositioning their limbs more rapidly in the
> air, but by applying greater support forces to the ground
> should be of interest to coaches and athletes on this group:
>
> Weyand PG, Sternlight DB, Bellizzi M & Wright S Faster
> top running speeds are achieved with greater ground
> forces not more rapid leg movements. J Appl Physiol 2000
> Nov; 89(5): 1991-9
>
> We twice tested the hypothesis that top running speeds are
> determined by the amount of force applied to the ground
> rather than how rapidly limbs are repositioned in the air.
>
> First, we compared the mechanics of 33 subjects of different
> sprinting abilities running at their top speeds on a level
> treadmill. Second, we compared the mechanics of declined (-6
> degrees) and inclined (+9 degrees) top-speed treadmill
> running in five subjects. For both tests, we used a
> treadmill-mounted force plate to measure the time between
> stance periods of the same foot (swing time, t(sw)) and the
> force applied to the running surface at top speed. To obtain
> the force relevant for speed, the force applied normal to
> the ground was divided by the weight of the body (W(b)) and
> averaged over the period of foot-ground contact
> (F(avge)/W(b)). The top speeds of the 33 subjects who
> completed the level treadmill protocol spanned a 1. 8-fold
> range from 6.2 to 11.1 m/s. Among these subjects, the
> regression of F(avge)/W(b) on top speed indicated that this
> force was
> 1.26 times greater for a runner with a top speed of 11.1 vs.
> 6.2 m/s.
>
> In contrast, the time taken to swing the limb into position
> for the next step (t(sw)) did not vary. Declined and
> inclined top speeds differed by 1.4-fold (9.96 vs. 7.10 m/s,
> respectively), with the faster declined top speeds being
> achieved with mass-specific support forces that were 1.3
> times greater (2.30 vs. 1.76 F(avge)/ W(b)) and minimum
> t(sw) that were similar (+8%).
>
> We conclude that human runners reach faster top speeds not
> by repositioning their limbs more rapidly in the air, but by
> applying greater support forces.

[Kerry Wils]

Michael Roose <trainerofathletes@email.com> wrote in message
news:<ouv5juk80uk0n7rl61t99bn4eq36763gmh@4ax.com>...
> This article showing that human runners reach faster top
> speeds, not by repositioning their limbs more rapidly in
> the air, but by applying greater support forces to the
> ground ...

They got paid to do this??

[Ivan Tirad]

I think this may not be as simple as you make it sound. Force
equals MASS x ACCELERATION... Are you saying that given the
same step frequency, the HEAVIER runner will be faster?

Force exerted on the ground is linearly related to weight.

"Michael Roose" <trainerofathletes@email.com> wrote in message
news:ouv5juk80uk0n7rl61t99bn4eq36763gmh@4ax.com...
> This article showing that human runners reach faster top
> speeds, not by repositioning their limbs more rapidly in the
> air, but by applying greater support forces to the ground
> should be of interest to coaches and athletes on this group:
>
> Weyand PG, Sternlight DB, Bellizzi M & Wright S Faster
> top running speeds are achieved with greater ground
> forces not more rapid leg movements. J Appl Physiol 2000
> Nov; 89(5): 1991-9
>
> We twice tested the hypothesis that top running speeds are
> determined by the amount of force applied to the ground
> rather than how rapidly limbs are repositioned in the air.
>
> First, we compared the mechanics of 33 subjects of different
> sprinting abilities running at their top speeds on a level
> treadmill. Second, we compared the mechanics of declined (-6
> degrees) and inclined (+9 degrees) top-speed treadmill
> running in five subjects. For both tests, we used a
> treadmill-mounted force plate to measure the time between
> stance periods of the same foot (swing time, t(sw)) and the
> force applied to the running surface at top speed. To obtain
> the force relevant for speed, the force applied normal to
> the ground was divided by the weight of the body (W(b)) and
> averaged over the period of foot-ground contact
> (F(avge)/W(b)). The top speeds of the 33 subjects who
> completed the level treadmill protocol spanned a 1. 8-fold
> range from 6.2 to 11.1 m/s. Among these subjects, the
> regression of F(avge)/W(b) on top speed indicated that this
> force was
> 1.26 times greater for a runner with a top speed of 11.1 vs.
> 6.2 m/s.
>
> In contrast, the time taken to swing the limb into position
> for the next step (t(sw)) did not vary. Declined and
> inclined top speeds differed by 1.4-fold (9.96 vs. 7.10 m/s,
> respectively), with the faster declined top speeds being
> achieved with mass-specific support forces that were 1.3
> times greater (2.30 vs. 1.76 F(avge)/ W(b)) and minimum
> t(sw) that were similar (+8%).
>
> We conclude that human runners reach faster top speeds not
> by repositioning their limbs more rapidly in the air, but by
> applying greater support forces.

[Mark]

Michael Roose <trainerofathletes@email.com> writes:
>This article showing that human runners reach faster top
>speeds, not by repositioning their limbs more rapidly in the
>air, but by applying greater support forces to the ground
>[...] Weyand PG, Sternlight DB, Bellizzi M & Wright S Faster
>top running speeds are achieved with greater ground forces
>not more rapid leg movements. J Appl Physiol 2000 Nov;
>89(5): 1991-9

That's exactly what I pointed out in the thread(s) on stride
length. Running is ballistic motion. So, the relevant variable
is push-off speed.

The 2 main variables in ballistic motion are initial push off
speed and push off angle. The angle is virtually fixed and
small for a given type of running and so has nearly no
relevance for running speed.

But leg speed (# steps/second) and stride length depend MAINLY
on push off angle not on push off speed.

For a given push-off speed, they have nearly no relevance for
running speed. So they are not relevant at all as far as
speed goes.

What they're relevant for is EFFICIENCY of motion -- since
there's more friction the faster you move your limbs, but also
more energy to get greater height for larger push off angles.
The greatest efficiency is the balance point of the two --
which is VERY low ... no matter what speed you're talking
about: maybe 200 steps/minute for sprint races.

A couple weeks ago, after doing the analysis, I decided to
change my running form to focus on push-off speed (and lower
stepping rates), as opposed to exclusively focusing on lower
stepping rates, and have seen the 200 meter time starting to
come down to 27's to just under 26 (so far).

There's actually a lot more improvement in store, since the
muscles required for push-off (as I've found out first-hand)
are basically the same ones used in the seated leg press; and
(in fact) to some degree even the inner thighs, gluts and hip
flexors and lower abs(!). Even the lower back!

Since I never do a lot of isolation exercises with those
(before now), there was the usual first-time-use 1-week
soreness period that comes, like when you play a new sport,
which is the tell-tale indication that you're (re-)deploying
new muscle groups ... and which is also an indication that
vast improvements are in store, with continued training. So, I
was VERY happy to find the initial 1-week soreness period.

The push-off speed jumped up from 7 meter/second to over 8
meters/second in that time frame (actual velocity is somewhat
less, given there's a 10-degree vertical ascent). At peak
strength that will definitely get over 9 meters/second and
probably as high as 10, leading to a time in the very low 20's
for a 200 meter split; 40's for a 400 meter. Already, it can
get well over 9 meters/second intermittently.

My stride (which, fixing push-off angle, DOES increase with
push off speed), went back up from 2.0 meters to over 2.3
meters, so far.

My target form for the 400 meter, in the short term, is a 48
second 200 stride/minute, 2.5 meter stride, which is very low
stepping rate for that kind of run. From there, it's a matter
of improved conditioning and fine-tuning (2.5 -> 2.6; 200 ->
205 or 210) to shave off the seconds.

You get burnout a lot quicker once you cross the 210 threshold
or so (the actual level depends on your conditioning) because
of all the energy loss from the inefficiency.

>We conclude that human runners reach faster top speeds not by
>repositioning their limbs more rapidly in the air, but by
>applying greater support forces.

... in perfect corroboration of the elementary Physics of
ballistic motion.

But, now that you let the cat out of the bag, I'm going to
have competition. I was hoping to deploy this method in secret
to get at a sudden and suprising level of world-class
competitiveness before anyone else learned your secret.

[Mark]

Michael Roose <trainerofathletes@email.com> writes:
>The top speeds of the 33 subjects who completed the level
>treadmill protocol spanned a 1. 8-fold range from 6.2 to 11.1
>m/s. Among these subjects, the regression of F(avge)/W(b) on
>top speed indicated that this force was
>1.26 times greater for a runner with a top speed of 11.1 vs.
> 6.2 m/s.

This is huge, if true. But it runs counter to expectation. I'd
expect to see a POWER law in force for force vs. speed, like
force = const * speed^2, so that the required force would be
3.24 times greater for that range, not 1.26 times. In general,
all other things being equal, doing any kind of motion on a
time scale X times smaller requires X^2 times more strength.
My reaction time is under 10ms, so I'm acutely aware of this
"inertia wall". The brain may operate at a 10ms time scale,
but actually moving that fast requires about 100 times the
strength for moving on a 'normal' 1/10 second time scale, like
most people do.

I'm pushing 175lbs on the seated leg press and the muscles
involved, as I found out, are primarily the ones involved in
push-off for fast running. I'm currently getting sustained top
speeds (on average) of
7.5 m/s, intermittent top speeds over 9. If what you're saying
is true, a sustained speed of 10 m/s would come at the
equivalent of doing 230-240 lbs on the seated leg press.

The machine in the weight room I use goes up to 250.

[Stephen Di]

In article <ouv5juk80uk0n7rl61t99bn4eq36763gmh@4ax.com>,
Michael Roose <trainerofathletes@email.com> wrote:

> Among these subjects, the regression of F(avge)/W(b) on top
> speed indicated that this force was 1.26 times greater for a
> runner with a top speed of 11.1 vs. 6.2 m/s.
>
> In contrast, the time taken to swing the limb into position
> for the next step (t(sw)) did not vary. Declined and
> inclined top speeds differed by 1.4-fold (9.96 vs. 7.10 m/s,
> respectively), with the faster declined top speeds being
> achieved with mass-specific support forces that were 1.3
> times greater (2.30 vs. 1.76 F(avge)/ W(b)) and minimum
> t(sw) that were similar (+8%).
>
> We conclude that human runners reach faster top speeds not
> by repositioning their limbs more rapidly in the air, but by
> applying greater support forces.

That may tell you that force is more important than leg speed,
but it does NOT tell you that force is the most important
factor, or even that it is substantially important. It may be,
for instance, that force pales in significance in comparison
to efficient use of force (including form, coordination, and
innate biomechanics.

Did the study report the Pearson product moment correlation
between force and speed? That's the information that is
important for practical purposes.

srd

[Knack]

Don't believe everything that you read; or don't read too much
into it. Common sense and traditional wisdom prove that weight
lifters are not great sprinters ;-)

If the body is to move faster then it must be trained to do
so. The best sprinters don't spend much time strengthening
their legs.

If greater support forces are as important to sprinting as the
study concludes, then why don't sprinters have calves that are
built like those of wilderness backpackers and mountain
climbers? Ever notice who the fastest guys on a pro football
team (tackle football) happen to be? They're the wide
receivers and secondary defenders who have the skinny lower
legs; ridiculously small calf muscles.

Michael Roose wrote:

> This article showing that human runners reach faster top
> speeds, not by repositioning their limbs more rapidly in the
> air, but by applying greater support forces to the ground
> should be of interest to coaches and athletes on this group:
>
> Weyand PG, Sternlight DB, Bellizzi M & Wright S Faster
> top running speeds are achieved with greater ground
> forces not more rapid leg movements. J Appl Physiol 2000
> Nov; 89(5): 1991-9
>
> We twice tested the hypothesis that top running speeds are
> determined by the amount of force applied to the ground
> rather than how rapidly limbs are repositioned in the air.
>
> First, we compared the mechanics of 33 subjects of different
> sprinting abilities running at their top speeds on a level
> treadmill. Second, we compared the mechanics of declined (-6
> degrees) and inclined (+9 degrees) top-speed treadmill
> running in five subjects. For both tests, we used a
> treadmill-mounted force plate to measure the time between
> stance periods of the same foot (swing time, t(sw)) and the
> force applied to the running surface at top speed. To obtain
> the force relevant for speed, the force applied normal to
> the ground was divided by the weight of the body (W(b)) and
> averaged over the period of foot-ground contact
> (F(avge)/W(b)). The top speeds of the 33 subjects who
> completed the level treadmill protocol spanned a 1. 8-fold
> range from 6.2 to 11.1 m/s. Among these subjects, the
> regression of F(avge)/W(b) on top speed indicated that this
> force was
> 1.26 times greater for a runner with a top speed of 11.1 vs.
> 6.2 m/s.
>
> In contrast, the time taken to swing the limb into position
> for the next step (t(sw)) did not vary. Declined and
> inclined top speeds differed by 1.4-fold (9.96 vs. 7.10 m/s,
> respectively), with the faster declined top speeds being
> achieved with mass-specific support forces that were 1.3
> times greater (2.30 vs. 1.76 F(avge)/ W(b)) and minimum
> t(sw) that were similar (+8%).
>
> We conclude that human runners reach faster top speeds not
> by repositioning their limbs more rapidly in the air, but by
> applying greater support forces.

[Knack]

Hey, you guys are missing the fishiest smelling statement in
the summary:

"...the time taken to swing the limb into position for the
next step (t(sw)) did not vary."

What the...?

It doesn't take an exercise scientist to realize that a runner
cannot improve his/her speed unless the limb swinging time can
be reduced! ;-) I mean, that's ultimately what the athlete is
trying to accomplish, isn't it? How else can he/she move
forward? ;-)

This brings to mind other pertinent questions, such as: Was
the treadmill a motorized or nonmotorized unit? It's sounding
like a motorized treadmill was used. If the researchers were
making comparisons by keeping one or more variables
controlled, such as controlling the belt speed at a constant
rate (taking force measurements at different constant speeds),
then for each runner at same belt speed... the leg swinging
time would be... no, the researchers couldn't be that thick
could they? ;-)

And has anyone wondered about how the normal force is
"averaged" throughout the contact time?

The researchers could've made a much better investigation
had they taken the more difficult (but proper) approach by
focusing *directly* on the horizontal force instead of the
(coincidental) normal force, which I suspect they have not
averaged correctly. There are ways that the maximum spike of
the horizontal force could've been obtained via modifying
the drive of the machine, and it shouldn't involve any
averaging either.

IMO, the design of the experiment was not that great. I'm
not buying their conclusion. Only a better study will prove
that to me.

Michael Roose wrote:

> This article showing that human runners reach faster top
> speeds, not by repositioning their limbs more rapidly in the
> air, but by applying greater support forces to the ground
> should be of interest to coaches and athletes on this group:
>
> Weyand PG, Sternlight DB, Bellizzi M & Wright S Faster
> top running speeds are achieved with greater ground
> forces not more rapid leg movements. J Appl Physiol 2000
> Nov; 89(5): 1991-9
>
> We twice tested the hypothesis that top running speeds are
> determined by the amount of force applied to the ground
> rather than how rapidly limbs are repositioned in the air.
>
> First, we compared the mechanics of 33 subjects of different
> sprinting abilities running at their top speeds on a level
> treadmill. Second, we compared the mechanics of declined (-6
> degrees) and inclined (+9 degrees) top-speed treadmill
> running in five subjects. For both tests, we used a
> treadmill-mounted force plate to measure the time between
> stance periods of the same foot (swing time, t(sw)) and the
> force applied to the running surface at top speed. To obtain
> the force relevant for speed, the force applied normal to
> the ground was divided by the weight of the body (W(b)) and
> averaged over the period of foot-ground contact
> (F(avge)/W(b)). The top speeds of the 33 subjects who
> completed the level treadmill protocol spanned a 1. 8-fold
> range from 6.2 to 11.1 m/s. Among these subjects, the
> regression of F(avge)/W(b) on top speed indicated that this
> force was
> 1.26 times greater for a runner with a top speed of 11.1 vs.
> 6.2 m/s.
>
> In contrast, the time taken to swing the limb into position
> for the next step (t(sw)) did not vary. Declined and
> inclined top speeds differed by 1.4-fold (9.96 vs. 7.10 m/s,
> respectively), with the faster declined top speeds being
> achieved with mass-specific support forces that were 1.3
> times greater (2.30 vs. 1.76 F(avge)/ W(b)) and minimum
> t(sw) that were similar (+8%).
>
> We conclude that human runners reach faster top speeds not
> by repositioning their limbs more rapidly in the air, but by
> applying greater support forces.

[Michael Ro]

Yep.

======================================================

On Mon, 15 Jul 2002 10:49:56 -0700, "Eduardo Suastegui"
<esuastegui701@esmartweb.com> wrote:

|Interesting. Here is a link to the abstract: |http://www.uth-
.tmc.edu/apstracts/2000/jap/September/438a.html
|
|So basically, this is saying, don't elongate your stride and
don't increase |your turn-over to achieve greater speed. For
instance, at
|http://www.fasterthangravity.com/Speedquesanspg.htm we read:
|
|"The drills we do to improve top end speed are not really
|accomplishing what
|we think they are. Step frequencies and contact lengths are
NOT the secret |to top speed.
|
|"How do we know this? The range of stride frequency between
|runners at
|various speeds is actually narrow. There is little
variation in step |frequency Also, contact length at
intermediate and highs speeds does not |vary all that much
between runners either."
|
|Now, how do we explain that mid to long-distance world class
runners seem to |settle at a turnover rate of about 180
steps/minute, while their sprinting, |short-distance
counterparts implement a higher turnover? The force findings
|aren't exactly surprising, btw. Compare the legs of a 100
meter sprinter |with those of a 5K runner and you will have
little doubt as to who is |exerting the greatest force on
terra firma.
|
|From my own personal experience, I gain speed not by
reaching forward
|(elongating my stride) or by increasing turnover rate, but by
|pushing back
|on the road with increased . . . you guessed it, force.
Using Ozzie's |analogy, he would say to increase speed by
increasing the forward lean, then |catching yourself; and
this, too, is a force equation, because the "catch" |is
halting the force of gravity. BTW, Ozzie's "catch yourself as
you fall |forward" picture seems to fit this research quite
well. Also in <>, we read:
|
|"Why do we have so many problems with this?
|
|"The problem is the way we analyze maximum velocity
|mechanics. We imagine
|propulsion, when there really isn't any. We believe the
secret is in |horizontal velocity, when, in actuality, peak
vertical ground reaction |forces are 5 to 10 times greater
than peak horizontal forces.
|
|"Is this some kind of paradox?
|
|"Not really-think of it this way: If we run at a constant
|speed against no
|air resistance, the forces that increase forward velocity
before take-off |simply offset the breaking forces that
decrease the body's velocity on |landing. Thus, they 'cancel
each other out.' As a result, we can say that |the net
horizontal forces at steady speed running are really...zero.
|Horizontal force does NOT explain the differences in top
speed. This is |exactly what the contemporary research makes
clear. We can challenge this by |arguing that treadmill
testing (standard for human locomotion research) does |not
duplicate the demands of actual sprinting, yet even if we were
to |compare the way athletes sprint uphill or downhill, or if
we were to change |the characteristics of the running surface,
the basic mechanical variables |are not affected."
|
|Of course, the phrase "at steady speed" conveniently
oversimplifies. |Sprinters--and other runners, for that
matter--must *accelerate* in the |horizontal plane to go from
one speed to another (from 0 to top running |speed), and
mass(your weight)*acceleration = FORCE. Add to this that
runners |do not run in a frictionless/lossless, environment,
and horizontal force of |some sort must be applied to produce
forward motion.

[proman]

Kerry Wilson wrote:
> Michael Roose <trainerofathletes@email.com> wrote in message
> news:<ouv5juk80uk0n7rl61t99bn4eq36763gmh@4ax.com>...
>
>>This article showing that human runners reach faster top
>>speeds, not by repositioning their limbs more rapidly in
>>the air, but by applying greater support forces to the
>>ground ...
>
>
> They got paid to do this??

yes, you paid for it on Apr 15.

[Michael Ro]

On Tue, 16 Jul 2002 16:06:12 -0400, "Ivan Tirado"
<ivanhoek@coqui.net> wrote:

|I think this may not be as simple as you make it sound. Force
equals MASS x |ACCELERATION... Are you saying that given the
same step frequency, the |HEAVIER runner will be faster?
|
|Force exerted on the ground is linearly related to weight.

Running is not only force absorption but is relative to one's
ability to generate force. Hence, the myotatic reflex issue.

[Mark]

Eduardo Suastegui" <esuastegui701@esmartweb.com> writes:
>Interesting. Here is a link to the abstract: http://www.uth.-
>tmc.edu/apstracts/2000/jap/September/438a.html
>
>So basically, this is saying, don't elongate your stride and
>don't increase your turn-over to achieve greater speed.

It's saying quite the opposite. It says don't pay attention
to stride at all or turn-over, when addressing the question
of speed; but pay attention only to how fast you push off
the ground.

And the reason that means the opposite (that you SHOULD
elongate your stride) is that the OTHER factor -- increased
friction from faster motion from the limbs -- should be
minimized to get the maximum efficiency and minimum loss of
energy and burn out.

That means, for a given push-off speed, increase the angle of
ascent to get a greater turn-over time between stride and ...
a greater stride length.

This balances against the negative effect of having to push
at a higher angle (and therefore push more against
gravity). But the balance point is MUCH smaller than what
you see 200m or 400m sprinters going at ... somewhere
closer to 200, not 240 steps/minute, and a VERY large
stride around 2.5 meters or more.

I saw only 2 runners do that in the 2000 Olympics: Michael
Johnson and Cathy Freeman. For Michael, especially during his
trial run, the stride was so large and leg motion so slow that
even the commentators picked it up, pointing out that he
looked like he was on a Sunday afternoon jog.

That's how the optimal form should look. I've done that
kind of form and it has both a very spectacular look and
feel to it.

>"How do we know this? The range of stride frequency between
>runners at various speeds is actually narrow.

... with the conspicuous, and telling, exceptions as
noted above.

[Mark]

"Eduardo Suastegui" <esuastegui701@esmartweb.com> writes:
>From my own personal experience, I gain speed not by reaching
>forward (elongating my stride) or by increasing turnover
>rate, but by pushing back
^^^^^^^^^^^^^^^^^^^^^^^
>on the road with increased . . . you guessed it, force.

Running is not walking. It's ballistic motion. Elongating
stride is not done by reaching forward (as for walking) but by
pushing off at a higher angle. Granted, the best East African
distance runners actually look like they're walking the run;
running, itself, is ballistic.

You're actually corroborating the conclusions I drew earlier
in this thread: push off speed is the primary variable for
running speed, not stride or stepping frequency -- but the
latter are the primary variables for running EFFICIENCY.

You'll get a higher push-off speed with a greater use of
force, which according to the study cited in the original
article is supposed to be in a 1.26 : 1.8 ratio (though I'm
arguing it should be 1.8^2 : 1.8 or
3.24 : 1.8 to get a increase in push-off speed of 1.8).

[Michael Ro]

On 18 Jul 2002 01:01:55 GMT, whopkins@alpha2.csd.uwm.edu
(Mark) wrote:

|There's actually a lot more improvement in store, since the
muscles |required for push-off (as I've found out first-hand)
are basically the |same ones used in the seated leg press; and
(in fact) to some degree |even the inner thighs, gluts and hip
flexors and lower abs(!). Even |the lower back!

Matching stength/power exercises in the weight room to a
sporting pursuit is neither necessary nor productive.

|Since I never do a lot of isolation exercises with those
(before now), there |was the usual first-time-use 1-week
soreness period that comes, like when you |play a new sport,
which is the tell-tale indication that you're (re-)deploying
|new muscle groups ... and which is also an indication that
vast improvements |are in store, with continued training.

There is no correlation between soreness (DOMS or other) and
athletic gains.

|>We conclude that human runners reach faster top speeds not
|>by repositioning their limbs more rapidly in the air, but by
|>applying greater support forces.

|... in perfect corroboration of the elementary Physics of
|ballistic motion.

Agreed.

|But, now that you let the cat out of the bag, I'm going to
have |competition. I was hoping to deploy this method in
secret to get |at a sudden and suprising level of world-class
competitiveness before |anyone else learned your secret.

Life is full of surprises.

[Michael Ro]

|>The top speeds of the 33 subjects who completed the level
|>treadmill protocol spanned a 1. 8-fold range from 6.2 to
|>11.1 m/s. Among these subjects, the regression of
|>F(avge)/W(b) on top speed indicated that this force was
|>1.26 times greater for a runner with a top speed of 11.1 vs.
|> 6.2 m/s.

On 18 Jul 2002 01:43:46 GMT, whopkins@alpha2.csd.uwm.edu
(Mark) wrote:

|This is huge, if true. But it runs counter to expectation.
I'd expect |to see a POWER law in force for force vs. speed,
like force = const * speed^2, |so that the required force
would be 3.24 times greater for that range, |not 1.26 times.

So did I but, alas, I was wrong.

| In general, all other things being equal, doing any kind
|of motion on a time scale X times smaller requires X^2 times
more strength. |My reaction time is under 10ms, so I'm acutely
aware of this "inertia wall". |The brain may operate at a 10ms
time scale, but actually moving that |fast requires about 100
times the strength for moving on a 'normal' 1/10 |second time
scale, like most people do.

In some instances, maybe.

|I'm pushing 175lbs on the seated leg press and the muscles
involved, |as I found out, are primarily the ones involved in
push-off for fast |running. I'm currently getting sustained
top speeds (on average) of
|7.5 m/s, intermittent top speeds over 9. If what you're
| saying is true,
|a sustained speed of 10 m/s would come at the equivalent of
doing 230-240 lbs |on the seated leg press.

Is this an open or closed chain press and what assimilation
would you actually expect from a seated position vs running?

[Eynshamrun]

"Ivan Tirado" <ivanhoek@coqui.net> wrote in message
news:<uj8v2frf8i6992@corp.supernews.com>...
> I think this may not be as simple as you make it sound.
> Force equals MASS x ACCELERATION... Are you saying that
> given the same step frequency, the HEAVIER runner will
> be faster?

No, the way to read this is that if two athletes are able to
produce the same force the lighter athlete will accelerate
quicker and therefore attain a higher speed sooner.

The athlete enters the quandary that an increase in muscle
mass may increase the amount of force that can be generated
but this is offset by the fact that the extra force generated
may not be sufficient to accelerate at the same rate given the
increase in mass.

Step frequency and stride length on their own have no bearing
on speed. It is only when both are maintained or increased
that an increase in speed occurs, i.e. maintaining stride
cadence with an increase stride length, or maintaining stride
length with an increase in cadence.

Too often I see athletes who overstride which results in a
lower cadence and therefore low speed.

[Bruce]

In rec.running whopkins@alpha2.csd.uwm.edu (Mark) wrote:

>I'm pushing 175lbs on the seated leg press and the muscles
>involved, as I found out, are primarily the ones involved in
>push-off for fast running. I'm currently getting sustained
>top speeds (on average) of
>7.5 m/s, intermittent top speeds over 9. If what you're
> saying is true, a sustained speed of 10 m/s would come
> at the equivalent of doing 230-240 lbs on the seated
> leg press.
>
>The machine in the weight room I use goes up to 250.

Why would you expect this to scale linearly? That would mean
some of these body builders doing 1500-2000 lbs could run
about 90 m/s.

[Michael Ro]

On Thu, 18 Jul 2002 20:00:41 -0700, Stephen Diamond
<stephend15@mindspring.com> wrote:

|That may tell you that force is more important than leg
speed, but it |does NOT tell you that force is the most
important factor, or even that |it is substantially important.
It may be, for instance, that force pales |in significance in
comparison to efficient use of force (including form,
|coordination, and innate biomechanics.

Perhaps.

|Did the study report the Pearson product moment correlation
between |force and speed?

No.

|That's the information that is important for practical
|purposes.

A simple force plate would suffice.

[Stephen Di]

In article <3D3977E8.8D2AA84A@hotmail.com>, Knack
<zok9@hotmail.com> wrote:

> Ever notice who the fastest guys on a pro football team
> (tackle football) happen to be? They're the wide receivers
> and secondary defenders who have the skinny lower legs;
> ridiculously small calf muscles.

Do they intentionally avoid developing their calf muscles,
because greater girth means less speed?

Stephen Diamond

[Michael Ro]

On Sat, 20 Jul 2002 10:47:04 -0400, Knack
<zok9@hotmail.com> wrote:

|Don't believe everything that you read; or don't read too
much into it. |Common sense and traditional wisdom prove that
weight lifters are not |great sprinters ;-)

LOL!

|If the body is to move faster then it must be trained to do
so. The best |sprinters don't spend much time strengthening
their legs.

LOL!

|If greater support forces are as important to sprinting as
the study |concludes, then why don't sprinters have calves
that are built like those |of wilderness backpackers and
mountain climbers? Ever notice who the |fastest guys on a pro
football team (tackle football) happen to be? |They're the
wide receivers and secondary defenders who have the skinny
|lower legs; ridiculously small calf muscles.

You're a tool, aren't you?

Btw, nice job seeing that hypertrophy has little to nothing
to do with power output. It's the only thing in this post
that is accurate.

[Knack]

Mark wrote:

> Michael Roose <trainerofathletes@email.com> writes:
> >This article showing that human runners reach faster top
> >speeds, not by repositioning their limbs more rapidly in
> >the air, but by applying greater support forces to the
> >ground [...] Weyand PG, Sternlight DB, Bellizzi M & Wright
> >S Faster top running speeds are achieved with greater
> >ground forces not more rapid leg movements. J Appl Physiol
> >2000 Nov; 89(5): 1991-9
>
> That's exactly what I pointed out in the thread(s) on stride
> length. Running is ballistic motion. So, the relevant
> variable is push-off speed.
>
> The 2 main variables in ballistic motion are initial push
> off speed and push off angle. The angle is virtually fixed
> and small for a given type of running and so has nearly no
> relevance for running speed.
>
> But leg speed (# steps/second) and stride length depend
> MAINLY on push off angle not on push off speed.
>
> For a given push-off speed, they have nearly no relevance
> for running speed. So they are not relevant at all as far as
> speed goes.
>
> What they're relevant for is EFFICIENCY of motion -- since
> there's more friction the faster you move your limbs, but
> also more energy to get greater height for larger push off
> angles. The greatest efficiency is the balance point of the
> two -- which is VERY low ... no matter what speed you're
> talking about: maybe 200 steps/minute for sprint races.
>
> A couple weeks ago, after doing the analysis, I decided to
> change my running form to focus on push-off speed (and lower
> stepping rates), as opposed to exclusively focusing on lower
> stepping rates, and have seen the 200 meter time starting to
> come down to 27's to just under 26 (so far).
>
> There's actually a lot more improvement in store, since the
> muscles required for push-off (as I've found out first-hand)
> are basically the same ones used in the seated leg press;
> and (in fact) to some degree even the inner thighs, gluts
> and hip flexors and lower abs(!). Even the lower back!
>
> Since I never do a lot of isolation exercises with those
> (before now), there was the usual first-time-use 1-week
> soreness period that comes, like when you play a new sport,
> which is the tell-tale indication that you're (re-)deploying
> new muscle groups ... and which is also an indication that
> vast improvements are in store, with continued training. So,
> I was VERY happy to find the initial 1-week soreness period.
>
> The push-off speed jumped up from 7 meter/second to over 8
> meters/second in that time frame (actual velocity is
> somewhat less, given there's a 10-degree vertical ascent).
> At peak strength that will definitely get over 9
> meters/second and probably as high as 10, leading to a time
> in the very low 20's for a 200 meter split; 40's for a 400
> meter. Already, it can get well over 9 meters/second
> intermittently.
>
> My stride (which, fixing push-off angle, DOES increase with
> push off speed), went back up from 2.0 meters to over 2.3
> meters, so far.
>
> My target form for the 400 meter, in the short term, is a 48
> second 200 stride/minute, 2.5 meter stride, which is very
> low stepping rate for that kind of run. From there, it's a
> matter of improved conditioning and fine-tuning (2.5 -> 2.6;
> 200 -> 205 or 210) to shave off the seconds.
>
> You get burnout a lot quicker once you cross the 210
> threshold or so (the actual level depends on your
> conditioning) because of all the energy loss from the
> inefficiency.
>
> >We conclude that human runners reach faster top speeds not
> >by repositioning their limbs more rapidly in the air, but
> >by applying greater support forces.
>
> ... in perfect corroboration of the elementary Physics of
> ballistic motion.
>
> But, now that you let the cat out of the bag, I'm going to
> have competition. I was hoping to deploy this method in
> secret to get at a sudden and suprising level of world-class
> competitiveness before anyone else learned your secret.

Hi Mark. The running feet really aren't coasting thru the air
in ballistic motion. Not only are they following a path
constrained by leg linkages, but of course the muscles are
active at all times.

The horizontal force (which apparently the researchers haven't
measured) is what really does the pushing of the body forward;
regardless of what angle the foot initially *leaves* contact
with the running surface, as it is swung forward.

The researchers instead investigated a coincidental force, the
normal force, because it was so much easier to measure. Just
mount force sensors on the treadmill deck beneath the belt.
That force is related only to traction, which opposes the
horizontal force. A runner (or a car) can have much more
traction than is actually used.

Ultimately, a runner can't move forward without an impulsive
force applied in the horizontal direction (directed opposite
the direction of travel) and without being able to swing the
legs forward quickly.

The study has a number of cracks in it. What do the
accomplished athletes have to say about sprinting technique? I
mean, they are the acknowledged experts, aren't they?

[Stephen Di]

In article <3D3DA09A.1D2291AF@hotmail.com>, Knack
<zok9@hotmail.com> wrote:

> It doesn't take an exercise scientist to realize that a
> runner cannot improve his/her speed unless the limb swinging
> time can be reduced! ;-) I mean, that's ultimately what the
> athlete is trying to accomplish, isn't it? How else can
> he/she move forward? ;-)

By propelling himself/herself through the air faster. Limb
swinging time decreases directly to the extent that the runner
stays close to the ground. One way of running faster would
seem to be staying closer to the ground and moving the limbs
faster. Another is by applying more force horizontally, at
push off. The relative importance of limb speed and propulsive
force is an empirical question, albeit one that, as you
pointed out, the study did not address, because it measured
the essentially irrelevant variable of vertical force. Finding
that irrelevant variable positively predictive (if you accept
that runners who apply force in the vertical as opposed to
horizontal plane are slower, it is _less_ than irrelevant) is
enough to raise questions in my mind as to the soundness of
its other conclusion, that limb speed doesn't matter.

Is this a peer reviewed journal? It is hard to imagine such
flaws getting by academic physiologists.

Stephen Diamond

[Michael Ro]

On Tue, 23 Jul 2002 14:29:46 -0400, Knack
<zok9@hotmail.com> wrote:

|Hey, you guys are missing the fishiest smelling statement in
the summary:

Nope.

|"...the time taken to swing the limb into position for the
|next step (t(sw)) did not vary."
|
|What the...?
|
|It doesn't take an exercise scientist to realize that a
runner cannot |improve his/her speed unless the limb swinging
time can be reduced! ;-) I |mean, that's ultimately what the
athlete is trying to accomplish, isn't |it? How else can
he/she move forward? ;-)

One of the components of accelerated limb swing time is to
produce greater push off the ground. You can get greater limb
swing acceleration by shortening your stride too.

|This brings to mind other pertinent questions, such as: |Was
the treadmill a motorized or nonmotorized unit? It's sounding
like a |motorized treadmill was used. If the researchers were
making comparisons |by keeping one or more variables
controlled, such as controlling the belt |speed at a constant
rate (taking force measurements at different constant
|speeds), then for each runner at same belt speed... the leg
swinging time |would be... no, the researchers couldn't be
that thick could they? ;-)

Who knows?

|And has anyone wondered about how the normal force is
"averaged" |throughout the contact time?

Yep.

|IMO, the design of the experiment was not that great. I'm
not buying their |conclusion. Only a better study will prove
that to me.

I agree.

[Van Bagnol]

In article <3D3DA09A.1D2291AF@hotmail.com>, Knack
<zok9@hotmail.com> wrote:

> The researchers could've made a much better investigation
> had they taken the more difficult (but proper) approach by
> focusing *directly* on the horizontal force instead of the
> (coincidental) normal force, which I suspect they have not
> averaged correctly. There are ways that the maximum spike of
> the horizontal force could've been obtained via modifying
> the drive of the machine, and it shouldn't involve any
> averaging either.
>
> IMO, the design of the experiment was not that great. I'm
> not buying their conclusion. Only a better study will prove
> that to me.

Though the post of the study did not mention the running pace,
the data merely suggest that the faster test subjects tended
to have a longer stride. After all, barring noticeable changes
in kinesthetic running form, runners with a more forceful kick
will be in the air longer before landing. However, without
horizontal force measurements, time-lapse photography (from
which horizontal forces can be gleaned from leg angles and
vertical forces), or stride measurements, I am only
speculating.

Observe a house cat walking ("cantering"?) rapidly vs running
("galloping"). Limb return is clearly more rapid, although
locomotion is slower, during the walk than the run.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com
...enjoys - Theatre / Windsurfing / Skydiving / Mountain
Biking ...feels - "Parang lumalakad ako sa loob ng paniginip"
...thinks - "An Error is Not a Mistake ... Unless You Refuse
to Correct It"

[Mark]

Knack <zok9@hotmail.com> writes:
>Hey, you guys are missing the fishiest smelling statement in
>the summary: "...the time taken to swing the limb into
>position for the next step (t(sw)) did not vary." What
>the...? It doesn't take an exercise scientist to realize that
>a runner cannot improve his/her speed unless the limb
>swinging time can be reduced!

Exactly the opposite.

Another even more striking effect to see a demonstration of
going from 4 meters/second to 8 meters/second while
simultaneously SLOWING the stride rate down from 240
strides/minute to 200.

I've done that. It has a spectacular feel to it, as well as
looking spectacular.

There can be no clearer demonstration than this of just how
dead on the researchers are and how completely wrong
conventional wisdom is about the relation between leg speed
and running speed. There simply is no relation between them.
They're independent variables.

[Michael Ro]

On 18 Jul 2002 02:23:13 GMT, whopkins@alpha2.csd.uwm.edu
(Mark) wrote:

|You're actually corroborating the conclusions I drew earlier
in this |thread: push off speed is the primary variable for
running speed, not |stride or stepping frequency -- but the
latter are the primary |variables for running EFFICIENCY.

You got it.

[Michael Ro]

On 18 Jul 2002 05:14:21 -0700, eynshamrunner@aol.com
(EynshamRunner) wrote:

|The athlete enters the quandary that an increase in muscle
mass may |increase the amount of force that can be generated
but this is offset |by the fact that the extra force generated
may not be sufficient to |accelerate at the same rate given
the increase in mass.

Yes, the quandary of the professional strength trainer.
Increasing muscular mass AND increasing relevant speed
measures. So back to turnover rates again and how do you
get better force absorption/generation transition in the
weight room?

No single answer. Plyometrics (drop-rebound and other loaded
work), ballistic lifts to heighten neural adaption in part or
in the entire body, some demonstrate greater turnover
characteristics by simply introducing hypertrophy.

|Step frequency and stride length on their own have no bearing
on |speed. It is only when both are maintained or increased
that an |increase in speed occurs, i.e. maintaining stride
cadence with an |increase stride length, or maintaining stride
length with an increase |in cadence.
|
|Too often I see athletes who overstride which results in a
lower |cadence and therefore low speed.

Especially if their speed coaches overemphasize stride length
in their training.

[Mark]

In article <3d374267.2752828@news.houston.sbcglobal.net>
nunya@damn.business.com (Bruce) writes:
>>I'm pushing 175lbs on the seated leg press...
>Why would you expect this to scale linearly? That would mean
>some of these body builders doing 1500-2000 lbs could run
>about 90 m/s.

The other problem with your question is that nobody does
1500-2000 lbs on the seated leg press. Not even I could
reach that, much less any other long-time or professional
weight lifter.

You're thinking of the INCLINED leg press, which is a whole
different animal.

The problem with my initial reply to the report is that they
said
1.26 increase in exerted force for 1.8 increase in speed --
which is actually SUB-LINEAR (which makes it even harder to
swallow, given the expectation of a general power law, like
quadratic). I thought they meant linear (since they used
regression), but that's actually more like the 0.4 power.

If you're going quadratic, then a 175lb seated leg press for
2.5 m/s would translate into a 325lb seated leg press
for 10 m/s.

So the real point of my reply is that the machine for this
exercise goes up to 250 lb. A linear law means I'd be doing 10
m/s at 230 lbs. So, we can put this to the test. My gut feel
is that pushing 250 lbs would bring an equivalent of a 8.8 -
9.0 meter/second sustained top speed.

[Sam]

"Michael Roose" <trainerofathletes@email.com> wrote in message
news:8sbcjuccpdm4qt78rqg1aurfsl77rpgabf@4ax.com...
> On 18 Jul 2002 01:01:55 GMT, whopkins@alpha2.csd.uwm.edu
> (Mark) wrote:
>
> |There's actually a lot more improvement in store, since the
> muscles |required for push-off (as I've found out
> first-hand) are basically the |same ones used in the seated
> leg press; and (in fact) to some degree |even the inner
> thighs, gluts and hip flexors and lower abs(!). Even |the
> lower back!
>
> Matching stength/power exercises in the weight room to a
> sporting pursuit is neither necessary nor productive.
Tell that to Heiki Rusko and the boys in Finland

>
> |Since I never do a lot of isolation exercises with those
> (before now),
there
> |was the usual first-time-use 1-week soreness period that
> comes, like when
you
> |play a new sport, which is the tell-tale indication
> that you're
(re-)deploying
> |new muscle groups ... and which is also an indication
> that vast
improvements
> |are in store, with continued training.
>
> There is no correlation between soreness (DOMS or other) and
> athletic gains.
>
>
> |>We conclude that human runners reach faster top speeds not
> |>by repositioning their limbs more rapidly in the air, but
> |>by applying greater support forces.
>
>
>
> |... in perfect corroboration of the elementary Physics of
> |ballistic
motion.
>
> Agreed.
>
>
> |But, now that you let the cat out of the bag, I'm going to
> have |competition. I was hoping to deploy this method in
> secret to get |at a sudden and suprising level of
> world-class competitiveness before |anyone else learned
> your secret.
>
> Life is full of surprises.

[Michael Ro]

On Sat, 20 Jul 2002 08:37:53 -0700, Stephen Diamond
<stephend15@mindspring.com> wrote:

|Do they intentionally avoid developing their calf muscles,
because |greater girth means less speed?

Yes, they go to doctors who perform secret operations that
purposefulluy retard the growth blah balh balh.

<rolling eyes

[Knack]

Michael Roose wrote:

> On Sat, 20 Jul 2002 10:47:04 -0400, Knack
> <zok9@hotmail.com> wrote:
>
> |Don't believe everything that you read; or don't read too
> much into it. |Common sense and traditional wisdom prove
> that weight lifters are not |great sprinters ;-)
>
> LOL!
>
> |If the body is to move faster then it must be trained to do
> so. The best |sprinters don't spend much time strengthening
> their legs.
>
> LOL!
>
> |If greater support forces are as important to sprinting as
> the study |concludes, then why don't sprinters have calves
> that are built like those |of wilderness backpackers and
> mountain climbers? Ever notice who the |fastest guys on a
> pro football team (tackle football) happen to be? |They're
> the wide receivers and secondary defenders who have the
> skinny |lower legs; ridiculously small calf muscles.
>
> You're a tool, aren't you?
>
> Btw, nice job seeing that hypertrophy has little to nothing
> to do with power output. It's the only thing in this post
> that is accurate.

Were there any accomplished sprinters involved in the study?
If so, who were they?

[Knack]

Hypertrophic athletes have *lots* of power. Look at each
weight class champion of the Olympics. From the smallest to to
the biggest guy, do you see any stringbeans?

Michael Roose wrote:

> On Sat, 20 Jul 2002 10:47:04 -0400, Knack
> <zok9@hotmail.com> wrote:
>
> |Don't believe everything that you read; or don't read too
> much into it. |Common sense and traditional wisdom prove
> that weight lifters are not |great sprinters ;-)
>
> LOL!
>
> |If the body is to move faster then it must be trained to do
> so. The best |sprinters don't spend much time strengthening
> their legs.
>
> LOL!
>
> |If greater support forces are as important to sprinting as
> the study |concludes, then why don't sprinters have calves
> that are built like those |of wilderness backpackers and
> mountain climbers? Ever notice who the |fastest guys on a
> pro football team (tackle football) happen to be? |They're
> the wide receivers and secondary defenders who have the
> skinny |lower legs; ridiculously small calf muscles.
>
> You're a tool, aren't you?
>
> Btw, nice job seeing that hypertrophy has little to nothing
> to do with power output. It's the only thing in this post
> that is accurate.

[Michael Ro]

On Tue, 23 Jul 2002 14:06:31 -0400, Knack
<zok9@hotmail.com> wrote:

|The researchers instead investigated a coincidental force,
the normal force,

Correct.

|because it was so much easier to measure. Just mount force
sensors on the |treadmill deck beneath the belt.

A little tougher than it may first sound.

|The study has a number of cracks in it.

Sure does. Most do.

[Bill Whedo]

Wow. Mr. Plagiarism Speaks! Whom do you steal your sparkling
commentary from, idiot? Still steaming over not having the
brains to acquire any certs, I see, and attacking those better
informed and smarter than yourself, that is, I guess, when
you're not nicking their work and peddling it as your own.

Do we take advice from common thieves? I think not. Get
lost, Roose.
--
Bill Whedon, CPFT World Fitness Free fitness info and
counselling http://www.worldfitness.org

Michael Roose wrote:
>
> On Tue, 23 Jul 2002 14:29:46 -0400, Knack
> <zok9@hotmail.com> wrote:
>
> |Hey, you guys are missing the fishiest smelling statement
> in the summary:
>
> Nope.
>
> |"...the time taken to swing the limb into position for the
> |next step (t(sw)) did not vary."
> |
> |What the...?
> |
> |It doesn't take an exercise scientist to realize that a
> runner cannot |improve his/her speed unless the limb
> swinging time can be reduced! ;-) I |mean, that's ultimately
> what the athlete is trying to accomplish, isn't |it? How
> else can he/she move forward? ;-)
>
> One of the components of accelerated limb swing time is to
> produce greater push off the ground. You can get greater
> limb swing acceleration by shortening your stride too.
>
> |This brings to mind other pertinent questions, such as:
> |Was the treadmill a motorized or nonmotorized unit? It's
> sounding like a |motorized treadmill was used. If the
> researchers were making comparisons |by keeping one or more
> variables controlled, such as controlling the belt |speed at
> a constant rate (taking force measurements at different
> constant |speeds), then for each runner at same belt
> speed... the leg swinging time |would be... no, the
> researchers couldn't be that thick could they? ;-)
>
> Who knows?
>
> |And has anyone wondered about how the normal force is
> "averaged" |throughout the contact time?
>
> Yep.
>
> |IMO, the design of the experiment was not that great. I'm
> not buying their |conclusion. Only a better study will prove
> that to me.
>
> I agree.

[Van Bagnol]

In article <qu6jjuovsru3vub66ppa412c7ciec605bn@4ax.com>,
Michael Roose <trainerofathletes@email.com> wrote:

> |If greater support forces are as important to sprinting as
> the study |concludes, then why don't sprinters have calves
> that are built like those |of wilderness backpackers and
> mountain climbers? Ever notice who the |fastest guys on a
> pro football team (tackle football) happen to be? |They're
> the wide receivers and secondary defenders who have the
> skinny |lower legs; ridiculously small calf muscles.
>
> You're a tool, aren't you?
>
> Btw, nice job seeing that hypertrophy has little to nothing
> to do with power output. It's the only thing in this post
> that is accurate.

That's a flawed inference. Who says hypertrophy has nothing to
do with power? While the _calves_ of sprinters are
proportionally small, look at the _thighs_. I'd noticed this
also; I hypothesized that the reduced moment arm enabled a
quicker return.

You'll also notice that the faster land mammals -- horses,
greyhounds, cheetahs -- have small fetlocks in relative to the
proximal leg muscles.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com
...enjoys - Theatre / Windsurfing / Skydiving / Mountain
Biking ...feels - "Parang lumalakad ako sa loob ng paniginip"
...thinks - "An Error is Not a Mistake ... Unless You Refuse
to Correct It"

[Mark]

In article
<stephend15-ED4DA2.14032623072002@news.mindspring.com> Stephen
Diamond <stephend15@mindspring.com> writes:
>By propelling himself/herself through the air faster. Limb
>swinging time decreases directly to the extent that the
>runner stays close to the ground.

However, the swinging time goes as the inverse of how close to
the ground you keep. For a given push-off speed, this variable
has almost no bearing on your speed.

The most dramatic way I can illustrate this is to run a 200
meter run in the mid 20's without going much over 200
strides/minute. That's almost jogging stride rate.

>One way of running faster would seem to be staying closer to
>the ground and moving the limbs faster. Another is by
>applying more force horizontally, at push off.

Only the latter is relevant.

>The relative importance of limb speed and propulsive force is
>an empirical question...

Running -- to say it again -- is ballistic motion. So, it's a
matter of simple Physics.

Take push-off speed (v) and leg speed (C) as the variables.
Each stride is a ballistic arc that takes place over a time
of T = 1/C. Your ground speed (s) is related to these by
the formula:

s^2 = v^2 - (g/2C)^2.

where g is about 9.8 meters/second^2. The latter, g/2C, is
negligible compared to the former v, and so has little
effect on s.

If you're pushing off the ground at 8 meters/second, then for
leg motions at rates 180 strides/minute (C = 3/second), and
240 strides/minute (C = 4/second), you get s^2 = (8^2 -
(4.9/3)^2) (meter/second)^2
vs.s^2 = (8^2 - (4.9/4)^2) (meter/second)^2 or s = 7.83
meter/second vs. 7.91 meter/second

We're talking the difference between moving your legs as a
jogger
(180) vs. moving them as a sprinter (240). Even across those
incredible extremes, it STILL hardly makes a
difference at all!

Limb speed doesn't matter. It's push-off speed that matters.
And you can move your limbs at any speed you want to get a
given push off speed by simply varying the angle of push off.
It's easy for me to demonstrate this and the visual effect is
VERY striking.

The reason for wanting to move the limbs at a given speed, as
I explain elsewhere in the thread, is something that's
entirely independent: power utilization efficiency.

You can also do the same analysis taking push off speed (v)
and maximum height (h) as the variables. You get the same
conclusions, with h = g/(8C^2), and s^2 = v^2 - 2gh.

You actually have to see this in action to appreciate just how
spectacular the effect is when you exploit this fact to go at
sprinting speeds (7.5 m/second, say, or more) while
simultaneously moving your legs at jogger pace (200 or so, or
less). It is much more efficient to run that way.

In fact, I'm shooting for a running form consisting of 160
steps, 2.5 meters/step, 3 1/3 steps/second. That would be a 48
second 400 meter run.

[Mark]

Stephen Diamond <stephend15@mindspring.com> writes:
>is enough to raise questions in my mind as to the soundness
>of its other conclusion, that limb speed doesn't matter.

Oh? Without varying the 200 strides/minute rate in the
slightest, I can easily get my running speed to vary anywhere
between 0 meters/second and 8 meters/second or more.

>Is this a peer reviewed journal? It is hard to imagine such
>flaws getting by academic physiologists.

There were no flaws in its conclusion, other than the
implied strength
vs. speed curve (discussed in another related thread). It is
dead on and precisely corroborates the fact that running
is ballistic motion.

[Michael Ro]

On Tue, 23 Jul 2002 14:03:26 -0700, Stephen Diamond
<stephend15@mindspring.com> wrote:

| Finding that
|irrelevant variable positively predictive (if you accept that
runners |who apply force in the vertical as opposed to
horizontal plane are |slower, it is _less_ than irrelevant) is
enough to raise questions in my |mind as to the soundness of
its other conclusion, that limb speed |doesn't matter.

HA! What a crock.

|Is this a peer reviewed journal? It is hard to imagine such
flaws |getting by academic physiologists.

There nothing wrong with the conclusions; just your jaded
interpretation of them.

[Stephen Di]

In article <van-889344.02512524072002@news.earthlink.net>, Van
Bagnol <van@crl.com.invalid> wrote:

> After all, barring noticeable changes in kinesthetic running
> form, runners with a more forceful kick will be in the air
> longer before landing.

Does the same form insure the same ratio between horizontal
and vertical force at different speeds? Well, I guess it
depends on how you define same, but the same runner running at
two different speeds will, I would think, _generally_ have a
greater proportion of force exerted in the horizontal plane.

But, there probably is something more like a negatively
accellerating relationship between horizontal and vertical
force the explains the result.

But the findings on limb speed are badly confounded, since
greater vertical force means slower limb speed, but that does
NOT preclude limb speed at the same horizontal force
predicting running speed too. And that's the relevant
relationship.

The study was a set up for misleading results.

Stephen Diamond

[Michael Ro]

On Thu, 18 Jul 2002 17:17:32 -0600, "Sam"
<marathonman@mindspring.com> wrote:

|> Matching stength/power exercises in the weight room to a
|> sporting pursuit is neither necessary nor productive.

| Tell that to Heiki Rusko and the boys in Finland

That's HeiKKo Rusko and he deals in high altitude training
which, if you knew your butt from a cabbage, is an entirely
different regimen.

[Gary Schna]

How does the poundage of a seated leg press compare
quantitatively to those for either a 1/2 or a 3/4 (full)
free-weight squat?

--
Gary Schnabl (Southwest) Detroit 2 miles NORTH of Canada -
Windsor, that is...

[Bruce Rich]

whopkins@alpha2.csd.uwm.edu (Mark) wrote in message
news:<ah7h2i$ma6$1@uwm.edu>...
> In article <3d374267.2752828@news.houston.sbcglobal.net>
> nunya@damn.business.com (Bruce) writes:
> >>I'm pushing 175lbs on the seated leg press...
> >Why would you expect this to scale linearly? That would
> >mean some of these body builders doing 1500-2000 lbs could
> >run about 90 m/s.
>
> The other problem with your question is that nobody does
> 1500-2000 lbs on the seated leg press. Not even I could
> reach that, much less any other long-time or professional
> weight lifter.
>
> You're thinking of the INCLINED leg press, which is a whole
> different animal.
>
> The problem with my initial reply to the report is that
> they said
> 1.26 increase in exerted force for 1.8 increase in speed --
> which is actually SUB-LINEAR (which makes it even harder
> to swallow, given the expectation of a general power law,
> like quadratic). I thought they meant linear (since they
> used regression), but that's actually more like the 0.4
> power.
>

Just some speculation here. I suspect the reason for the
sub-linear increase is the angle of the applied force. If the
higher force was applied at the same angle as the lower force,
the vertical component would lift the runner so high that he
would not get back to the ground in time for the next stride.
So the force is applied at a shallower angle, with a larger
percentage of it pushing the runner forward.

I don't think what you can press tells much about how fast you
can run. To run fast you must be able to apply the force at
the required speed.

> If you're going quadratic, then a 175lb seated leg press for
> 7.5 m/s would translate into a 325lb seated leg press for
> 10 m/s.
>
> So the real point of my reply is that the machine for this
> exercise goes up to 250 lb. A linear law means I'd be doing
> 10 m/s at 230 lbs. So, we can put this to the test. My gut
> feel is that pushing 250 lbs would bring an equivalent of a
> 8.8 - 9.0 meter/second sustained top speed.

[Robert Gru]

In article <ah7h2i$ma6$1@uwm.edu>, Mark
<whopkins@alpha2.csd.uwm.edu> wrote:

[snip]

>The problem with my initial reply to the report is that
>they said
>1.26 increase in exerted force for 1.8 increase in speed --
> which is actually SUB-LINEAR (which makes it even harder to
> swallow, given the expectation of a general power law, like
> quadratic). I thought they meant linear (since they used
> regression), but that's actually more like the 0.4 power.

There's nothing in those two numbers that argues against a
linear relationship.

y = a + bx is linear.

Let y = Force/(reference force) x = Speed/(reference speed) a
= 1.06 b = 1/9

This straight line will run straight through the point
provided (as will an infinite variety of other
straight lines).

The fun thing about having only 1 data point -- which is all
you're quoting -- is that one can put any kind of curves at
all through the point, be it linear, exponential, power law,
sinusoidal, ...

If we take a second point as being 1,1 (reference force
occurs at reference speed), the above line is still pretty
close. Knocking back a a little and increasing b is all that
is required to run through both points. (Computing the
correct values of a and b is left as an exercise to the
reader. :-)

--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and
amateur activities notes and links. Sagredo (Galileo Galilei)
"You present these recondite matters with too much evidence
and ease; this great facility makes them less appreciated than
they would be had they been presented in a more abstruse
manner." Two New Sciences

[Michael Ro]

On Mon, 22 Jul 2002 09:54:45 -0400, Knack
<zok9@hotmail.com> wrote:

|Were there any accomplished sprinters involved in the study?
If so, who were |they?

Call the authors.

[Sam]

"Knack" <zok9@hotmail.com> wrote in message
news:3D3C0EA5.1CE3AC64@hotmail.com...
>
>
> Michael Roose wrote:
>
> > On Sat, 20 Jul 2002 10:47:04 -0400, Knack
> > <zok9@hotmail.com> wrote:
> >
> > |Don't believe everything that you read; or don't read too
> > much into it. |Common sense and traditional wisdom prove
> > that weight lifters are not |great sprinters ;-)
> >
> > LOL!
> >
> > |If the body is to move faster then it must be trained to
> > do so. The
best
> > |sprinters don't spend much time strengthening their legs.
> >
> > LOL!
> >
> > |If greater support forces are as important to sprinting
> > as the study |concludes, then why don't sprinters have
> > calves that are built like
those
> > |of wilderness backpackers and mountain climbers? Ever
> > notice who the |fastest guys on a pro football team
> > (tackle football) happen to be? |They're the wide
> > receivers and secondary defenders who have the skinny
> > |lower legs; ridiculously small calf muscles.
> >
> > You're a tool, aren't you?
> >
> > Btw, nice job seeing that hypertrophy has little to
> > nothing to do with power output. It's the only thing in
> > this post that is accurate.
>
> Were there any accomplished sprinters involved in the study?
> If so, who
were
> they?\
I have not read the study, but current rules prohibit
the release of names of individuals from research.

[Michael Ro]

On Tue, 23 Jul 2002 13:49:18 -0400, Knack
<zok9@hotmail.com> wrote:

|Hypertrophic athletes have *lots* of power.

Some do, some don't. Depends on the movement.

Ever see Ronnie Coleman run? It's nasty; he cannot translate
force well at all; slow as a turtle.

|Look at each weight class champion |of the Olympics. From the
smallest to to the biggest guy, do you see any |stringbeans?

None but I also don't see tremendous hypertrophy compared to
the BBers. When training for the OLifts, there is little
emphasis on hypertrophy; the more experienced the lifter, the
more detailed to creating explosive power in the movements and
in all of their accessories.

Point being; hypertrophy means nothing unless it is hooked to
a well developed neural system that has learned/trained to
develop great force in the methods chosen.

[Michael Ro]

On Wed, 24 Jul 2002 09:35:49 GMT, Van Bagnol
<van@crl.com.invalid> wrote:

|That's a flawed inference. Who says hypertrophy has nothing
to do with |power?

I do. You can have significant hypertrophy and very little
power capabilities coupled with it. Ask your local BBer to
run. I have seen children more powerful. Ask him to jump. I
have seen 125 high school athletes with higher verticals.

| While the _calves_ of sprinters are proportionally
| small, look at
|the _thighs_. I'd noticed this also; I hypothesized that the
reduced |moment arm enabled a quicker return.

Quad/hamstring hypertrophy is common in sprinters however
it is not the muscle size that produces the power but their
ability to generate force. Force generation has much more
to do with neural capabilities than muscular cross
sectional area.

|You'll also notice that the faster land mammals -- horses,
greyhounds, |cheetahs -- have small fetlocks in relative to
the proximal leg muscles.

There you go.

[Stephen Di]

In article <ahpbil$fnt$1@uwm.edu>, whopkins@alpha2.csd.uwm.edu
(Mark) wrote:

> Stephen Diamond <stephend15@mindspring.com> writes:
> >is enough to raise questions in my mind as to the soundness
> >of its other conclusion, that limb speed doesn't matter.
>
> Oh? Without varying the 200 strides/minute rate in the
> slightest, I can easily get my running speed to vary
> anywhere between 0 meters/second and 8 meters/second
> or more.

Irrelevant. Your anecdote at most indicates that speed can be
increased by means other than increased limb speed. That does
NOT imply (simply as a matter of logic) than you cannot ALSO
increase running speed by increasing limb speed.
>
> >Is this a peer reviewed journal? It is hard to imagine such
> >flaws getting by academic physiologists.
>
> There were no flaws in its conclusion, other than the
> implied strength
> vs. speed curve (discussed in another related thread). It is
> dead on and precisely corroborates the fact that running
> is ballistic motion.

Who knows with any certain whether the _conclusion_ is flawed.
If it was, as you say, derivable from the obvious fact that
running is ballistic, then there would be little reason to do
an empirical study. You cannot rescue a flawed methodology by
expressing agreement with the conclusions of the study.

Some, including the poster I am responding to, are obviously
incompetent to evaluate a study's methods. I wonder why they
think otherwise. (Not really. The reason they think otherwise
is well exemplified here: they cannot even get to base 1 by
distinguishing the methods from the conclusions of a study.

Stephen Diamond

[Stephen Di]

In article <ahp9ob$dk3$1@uwm.edu>, whopkins@alpha2.csd.uwm.edu
(Mark) wrote:

> In article
> <stephend15-ED4DA2.14032623072002@news.mindspring.com>
> Stephen Diamond <stephend15@mindspring.com> writes:
> >By propelling himself/herself through the air faster. Limb
> >swinging time decreases directly to the extent that the
> >runner stays close to the ground.
>
> However, the swinging time goes as the inverse of how close
> to the ground you keep. For a given push-off speed, this
> variable has almost no bearing on your speed.

>
> The most dramatic way I can illustrate this is to run a 200
> meter run in the mid 20's without going much over 200
> strides/minute. That's almost jogging stride rate.
>
> >One way of running faster would seem to be staying closer
> >to the ground and moving the limbs faster. Another is by
> >applying more force horizontally, at push off.
>
> Only the latter is relevant.
>
> >The relative importance of limb speed and propulsive force
> >is an empirical question...
>
> Running -- to say it again -- is ballistic motion. So, it's
> a matter of simple Physics.
>
> Take push-off speed (v) and leg speed (C) as the variables.
> Each stride is a ballistic arc that takes place over a time
> of T = 1/C. Your ground speed (s) is related to these by the
> formula:
>
> s^2 = v^2 - (g/2C)^2.
>
> where g is about 9.8 meters/second^2. The latter, g/2C, is
> negligible compared to the former v, and so has little
> effect on s.
>
> If you're pushing off the ground at 8 meters/second, then
> for leg motions at rates 180 strides/minute (C = 3/second),
> and 240 strides/minute (C = 4/second), you get s^2 = (8^2 -
> (4.9/3)^2) (meter/second)^2
> vs.s^2 = (8^2 - (4.9/4)^2) (meter/second)^2 or s = 7.83
> meter/second vs. 7.91 meter/second
>
> We're talking the difference between moving your legs as
> a jogger
> (180) vs. moving them as a sprinter (240). Even across those
> incredible extremes, it STILL hardly makes a
> difference at all!
>
> Limb speed doesn't matter. It's push-off speed that matters.
> And you can move your limbs at any speed you want to get a
> given push off speed by simply varying the angle of push
> off. It's easy for me to demonstrate this and the visual
> effect is VERY striking.
>
> The reason for wanting to move the limbs at a given speed,
> as I explain elsewhere in the thread, is something that's
> entirely independent: power utilization efficiency.
>
> You can also do the same analysis taking push off speed (v)
> and maximum height (h) as the variables. You get the same
> conclusions, with h = g/(8C^2), and s^2 = v^2 - 2gh.

You're correct. Please allow me to apologize for my previous
irritated posting in response to you. You have made the
critical point, largely a priori. (The empirical input is the
real world differences in leg speed.)

I think you draw the wrong conclusion. In fact I'm pretty sure
of it. I'll continue this at the end, after finishing
responding directly.
>
> You actually have to see this in action to appreciate just
> how spectacular the effect is when you exploit this fact to
> go at sprinting speeds (7.5 m/second, say, or more) while
> simultaneously moving your legs at jogger pace (200 or so,
> or less). It is much more efficient to run that way.

A very interesting result, but one which cuts against your
contention. You are in effect proving that limb speed has a
significance that cannot be completely predicted by the
ballistec model.

The model I proposed is ballistic in character. And, you are
right that once that is known, provided we know the range of
limb speeds (but even to the roughest approximation), it just
falls out of the equations that pushoff speed predominates
over limb speed.

I take that to be a refutation of the ballistic model I
proposed--or that you entertain on whatever basis. The very
fact that sprinters double the leg speed of joggers shows that
leg speed is very relevant. And if you find that maintaining
the same leg speed is more important, you too are recognizing
that leg speed has a significance than goes beyond the
ballistic model.

Of course, if the ballistic model fails, it is because the
only phase that is not of ballistic significance affects
running speed in some other way than those ways the ballistic
model says suffice. That is the only conceivable point at
which the ballistic model fails.

I think that the way leg speed affects running speed is that
the faster the legs go, the shorten the duration of touchdown.
That is, the faster your legs move, the more nearly ballistic
you are. The runner who moves his legs slowly cannot help but
move slowly through the touchdown phase. The touchdown phase
is important because it decreases the time in the air. But,
with a few probably known parameters, that effect could also
be determined from the equations. But I have no idea about how
much time touchdown takes at the extremes, as a function of
leg speed.

Thee is however, another effect of touchdown, which is what
makes the question empirical. It is the braking effect of
touchdown, greater as touchdown time increases.

Another unmentioned flaw in the study is that limb speed and
force are not independent variables. All else being equal, the
greater the vertical force (the only force actually
measured--the study's most obvious aflaw) the slow the limb
speed (higher arc). So limb speed in the study cannot be
expected to predict speed, because it is correlated in the
reverse direction with a variable which did predict speed (for
reasons not ascertainable and not intuitively obvious, since
we are NOT here talking about _horizontal_ force. So, the
study doesn't warrant the conclusion that you can't get much
faster by learning to move your limbs faster.

Stephen Diamond


>
> In fact, I'm shooting for a running form consisting of 160
> steps, 2.5 meters/step, 3 1/3 steps/second. That would be a
> 48 second 400 meter run.

[Sam]

"Michael Roose" <trainerofathletes@email.com> wrote in message
news:ijnejucldbi5703nfr84jgp7rinqvka0ck@4ax.com...
> On Thu, 18 Jul 2002 17:17:32 -0600, "Sam"
> <marathonman@mindspring.com> wrote:
>
> |> Matching stength/power exercises in the weight room to a
> |> sporting pursuit is neither necessary nor productive.
>
>
> | Tell that to Heiki Rusko and the boys in
> | Finland
>
> That's HeiKKo Rusko and he deals in high altitude training
> which, if you knew your butt from a cabbage, is an entirely
> different regimen.

So sorry for the mistyping. I actually have met
the man. You might want to know he has done
studies with explosive strength training and 5K
runners. Do a PubMed search. He is not just
focused on one thing.

[Michael Ro]

On Fri, 19 Jul 2002 08:10:41 GMT, "Gary Schnabl"
<badBadger@badBadger.com> wrote:

| How does the poundage of a seated leg press compare
| quantitatively to
|those for either a 1/2 or a 3/4 (full) free-weight squat?

It doesn't.

[Stephen Di]

In article <747a5d11.0207191908.18cd3d8e@posting.google.com>,
bsr3997@my-deja.com (Bruce Richmond) wrote:

> I suspect the reason for the sub-linear increase is the
> angle of the applied force. If the higher force was applied
> at the same angle as the lower force, the vertical component
> would lift the runner so high that he would not get back to
> the ground in time for the next stride.

Which, I think, is another way of saying that the application
of increased force is self-limiting; that would make it,
prima facie, an unlikely candidate for the most important
factor in speed.

I still would like to know what percentage of the total
variance in speed was accounted for by force.

srd

[Michael Ro]

On 19 Jul 2002 20:08:15 -0700, bsr3997@my-deja.com (Bruce
Richmond) wrote:

|I don't think what you can press tells much about how fast
you can |run.

No correlation whatsoever.

| To run fast you must be able to apply the force at the
| required
|speed.

One of many, but the most important, component of speed.

[Stephen Di]

In article <747a5d11.0207191908.18cd3d8e@posting.google.com>,
bsr3997@my-deja.com (Bruce Richmond) wrote:

> I don't think what you can press tells much about how fast
> you can run. To run fast you must be able to apply the force
> at the required speed.

Which do you mean:

1. To run fast, you must be able to apply force at a
rapid rate.

2. To run fast, you must be able to apply force at a rate
appropriate for the level of force.

It seems to me #1 predicts that force and foot speed interact
in predicting running speed. Then, the study, which didn't
report interactions would be pretty misleading.

#2 speaks to efficiency.

srd

[Michael Ro]

On Mon, 22 Jul 2002 12:42:45 -0600, "Sam"
<marathonman@mindspring.com> wrote:

| I have not read the study, but current rules prohibit the
| release of
|names of individuals from research.

Unless they have signed a waiver to allow such, that is
correct.

[Van Bagnol]

In article <3u6tjucpgm6csu3m4784ggufnk16libnhp@4ax.com>,
Michael Roose <trainerofathletes@email.com> wrote:

> On Wed, 24 Jul 2002 09:35:49 GMT, Van Bagnol
> <van@crl.com.invalid> wrote:
>
> |That's a flawed inference. Who says hypertrophy has nothing
> to do with |power?
>
> I do.

Your reply was suggesting that small calf size in sprinters
was proof that hypertrophy and power were independent. You
did not address quad/hamstring size, which in the next post,
you conceded:

> Quad/hamstring hypertrophy is common in sprinters [...]

My post was proposing that the proportion of quad/hamstring
size to calf size might be a factor. More specifically, the
reduced moment arm evidenced by the relative reduction in mass
on the distal portions of the limbs relative to the proximal.

> You can have significant hypertrophy and very little power
> capabilities coupled with it.

Agreed.

> Ask your local BBer to run. I have seen children more
> powerful.

Ask a child to leg press 400 lbs. I've seen bodybuilders
more powerful.

> Quad/hamstring hypertrophy is common in sprinters [...]

Then hypertrophy and power are somehow associated with
each other.

> [...] however it is not the muscle size that produces the
> power but their ability to generate force. Force generation
> has much more to do with neural capabilities than muscular
> cross sectional area.

I agree with the first sentence but not with the second.
Strictly speaking, the combination of neural capabilities and
muscle size generate power. It is not muscle size that
produces power, but muscle size that generates force. (The
greater cross-sectional area contracting [or if you want to
factor out sarcoplasmic hypertrophy, the greater number of
actin-myosin fibrils], the more force.) Tightly coupled neural
recruitment actuates more muscle contraction within a shorter
interval of time. Because power is force per unit time,
greater force in less time produces more power.

> |You'll also notice that the faster land mammals -- horses,
> greyhounds, |cheetahs -- have small fetlocks relative to the
> proximal leg muscles.
>
> There you go.

No pun intended, I gather?

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com
...enjoys - Theatre / Windsurfing / Skydiving / Mountain
Biking ...feels - "Parang lumalakad ako sa loob ng paniginip"
...thinks - "An Error is Not a Mistake ... Unless You Refuse
to Correct It"

[Stephen Di]

In article
<stephend15-2EF7C3.14513925072002@news.mindspring.com>,
Stephen Diamond <stephend15@mindspring.com> wrote:

> if you find that maintaining the same leg speed is more
> important,

Meant to write "is more efficient"

srd

[Michael Ro]

On Fri, 19 Jul 2002 06:17:31 -0600, "Sam"
<marathonman@mindspring.com> wrote:

|> That's HeiKKo Rusko and he deals in high altitude training
|> which, if you knew your butt from a cabbage, is an entirely
|> different regimen.
|
|You might want to know he has done studies with explosive
strength training |and 5K runners.

I've read his work. Several of them. Including this one.

http://jap.physiology.org/cgi/content/full/86/5/1527

"Explosive-strength training sessions lasted for 15-90 min and
consisted of various sprints (5-10) · (20-100 m) and jumping
exercises [alternative jumps, bilateral countermovement, drop
and hurdle jumps, and 1-legged, 5-jump (5J) tests] without
additional weight or with the barbell on the shoulders and
leg-press and knee extensor-flexor exercises with low loads
but high or maximal movement velocities (30-200
contractions/training session and 5-20 repetitions/set). "

Two problems. I consider this very "low-level expo training
(compared to many of the methods I use including OLifts and
their variations.) and..

"These observations are mainly based on experiments in which
heavy-resistance strength training has predominated and the
subjects have been previously untrained."

Guess what. Untrained subjects nearly always improve
performance because they are UNTRAINED. This last statement
alone invalidates this "research" (if you can call it that
since "10 experimental (E) and 8 control (C) endurance
athletes trained" is an inconclusive number of participants)
for a TRAINED athlete.

One more thing. Using any explo training on UNTRAINED athletes
may be fine for research but it flat is unethical for any
strength trainer to perform in real life athletes.

[Bruce Rich]

Stephen Diamond <stephend15@mindspring.com> wrote in message
news:<stephend15-D4246A.20284919072002@news.mindspring.com>...
> In article
> <747a5d11.0207191908.18cd3d8e@posting.google.com>,
> bsr3997@my-deja.com (Bruce Richmond) wrote:
>
> > I suspect the reason for the sub-linear increase is the
> > angle of the applied force. If the higher force was
> > applied at the same angle as the lower force, the vertical
> > component would lift the runner so high that he would not
> > get back to the ground in time for the next stride.
>
> Which, I think, is another way of saying that the
> application of increased force is self-limiting; that would
> make it, prima facie, an unlikely candidate for the most
> important factor in speed.
>

Not exactly. The vertical component of the force causes the
runner to go up, while gravity pulls him back down. His mass
travels in an arcing trajectory. The height of the arc will be
the determining factor for the runner's tempo, how many
strides per minute he can make. He can't start the next stride
until he gets down. And he had better make that stride when he
comes down or he will fall on his face.

As I said in the previous post, if more force is applied at
the same angle, the vertical component is larger, which would
cause the runner to make long bounding strides. By lowering
the angle appropriately the height of the arc could be reduced
to the same as before, and the additional force would carry
the runner further in the same time as before, and at the same
tempo. The trajectory of the arc will be flatter.

The runner would not need to stretch his stride out to gain
the speed above. The difference comes from the flight
distance, when neither of his feet are on the ground. And as I
said before, the tempo would be the same, so he wouldn't have
to bring his foot forward for the next step any faster than he
did before.

What appears to be the limiting factor is that not only must
more force be applied, but it must be done faster. If you
have ever peddled a bicycle down a hill and not been able to
move your feet fast enough to make any difference you know
what I'm talking about. You can only apply force if you can
move fast enough to keep up. And since the tempo of the
runner is still the same, the part where this limit shows up
is on the push off.

Does this make sense to you? I'm no expert when it comes to
running. My analysis above is based purely on physics. And I
don't think any single aspect can be called most important to
running fast.

> I still would like to know what percentage of the total
> variance in speed was accounted for by force.
>
> srd

[Bruce Rich]

Stephen Diamond <stephend15@mindspring.com> wrote in message
news:<stephend15-5A028E.21010319072002@news.mindspring.com>...
> In article
> <747a5d11.0207191908.18cd3d8e@posting.google.com>,
> bsr3997@my-deja.com (Bruce Richmond) wrote:
>
> > I don't think what you can press tells much about how fast
> > you can run. To run fast you must be able to apply the
> > force at the required speed.
>
> Which do you mean:
>
> 1. To run fast, you must be able to apply force at a rapid
> rate.
>

Yes

> 2. To run fast, you must be able to apply force at a rate
> appropriate for the level of force.
>
> It seems to me #1 predicts that force and foot speed
> interact in predicting running speed. Then, the study, which
> didn't report interactions would be pretty misleading.
>

Agreed

> #2 speaks to efficiency.
>
> srd

[Michael Ro]

On Thu, 25 Jul 2002 12:36:59 GMT, Van Bagnol
<van@crl.com.invalid> wrote:

|Your reply was suggesting that small calf size in sprinters
was proof |that hypertrophy and power were independent. You
did not address |quad/hamstring size, which in the next post,
you conceded:

Your accepted an incorrect implication.

|> Quad/hamstring hypertrophy is common in sprinters [...]
|
|My post was proposing that the proportion of quad/hamstring
size to calf |size might be a factor.

It can be.

| More specifically, the reduced moment arm
|evidenced by the relative reduction in mass on the distal
portions of |the limbs relative to the proximal.

No problem with that.

|Ask a child to leg press 400 lbs. I've seen bodybuilders
more powerful.

Your definition of power is not one acce[ted among
professional strength trainers.

|> Quad/hamstring hypertrophy is common in sprinters [...]
|
|Then hypertrophy and power are somehow associated with
each other.

Sometimes.

|> [...] however it is not the muscle size that produces the
|> power but their ability to generate force. Force generation
|> has much more to do with neural capabilities than muscular
|> cross sectional area.
|
|I agree with the first sentence but not with the second.
Strictly |speaking, the combination of neural capabilities and
muscle size |generate power. It is not muscle size that
produces power, but muscle |size that generates force.

In correct. Neural capabilities handle the force equation.
Muscles are nothing more than strands of amino acids and
chemicals that are excited by the neural system into motion.

[Sam]

"Michael Roose" <trainerofathletes@email.com> wrote in message
news:plogju0qd2gd4488ec5kvq14dg4ncq7r74@4ax.com...
> On Fri, 19 Jul 2002 06:17:31 -0600, "Sam"
> <marathonman@mindspring.com> wrote:
>
> |> That's HeiKKo Rusko and he deals in high altitude
> |> training which, if you knew your butt from a cabbage, is
> |> an entirely different regimen.
> |
> |You might want to know he has done studies with explosive
> strength
training
> |and 5K runners.
>
> I've read his work. Several of them. Including this one.

Then you should have known that he does more than
merely look at altitude.

>
> http://jap.physiology.org/cgi/content/full/86/5/1527
>
>
> "Explosive-strength training sessions lasted for 15-90 min
> and consisted of various sprints (5-10) · (20-100 m) and
> jumping exercises [alternative jumps, bilateral
> countermovement, drop and hurdle jumps, and 1-legged, 5-jump
> (5J) tests] without additional weight or with the barbell on
> the shoulders and leg-press and knee extensor-flexor
> exercises with low loads but high or maximal movement
> velocities (30-200 contractions/training session and 5-20
> repetitions/set). "
>
> Two problems. I consider this very "low-level expo training
> (compared to many of the methods I use including OLifts and
> their variations.) and..

That is subjective (in terms of what low level is)
and open to legitimate discussion and research.
One might argue that higher levels of resistance
might lead to more improvement. Perhaps you can do
the research and publish the work as Rusko's group
has done. I did not read each line, but I did not
see, in a quick perusal, where the researchers or
I called it high level.

>
> "These observations are mainly based on experiments in which
> heavy-resistance strength training has predominated and the
> subjects have been previously untrained."

>
> Guess what. Untrained subjects nearly always improve
> performance because they are UNTRAINED. This last
> statement alone invalidates this "research" (if you
> can call it that since "10 experimental (E) and 8
> control (C) endurance athletes trained" is an
> inconclusive number of participants) for a TRAINED
> athlete.

The athletes in the study you provided the link to
clearly states the athletes were trained so there
could be some application to other trained
athletes. Taking things out of context here
Rooser, the comment above is from the discussion
section talking about PAST research that dealt
with untrained athletes as a historical basis for
the research. This research dealt with
well-trained athletes. From what I can tell
looking at the paper on line (the hard copy is at
work), the runners were orienteers who were
capable of running a 5K time of ~18min (perhaps
world class for orienteers, I have no idea), but I
would guess a time many in this group can and have
run so it is quite applicable. Also, it is clear
that the comment does not refer to the current
study since the current study deals with explosive
training and the reference is to heavy resistance
training. The numbers are small and more research
needs to be done (that is true of all science).
How about adding to the body of knowledge with
research and submit it to JAP like Paavolainen
did? I never stated that is conclusive merely
noted that the research had been done and that it
should cause people to pause and consider it.

Did you intentionally clip out of context to
mislead others? And you get onto me for leaving
out a "k"? tsk, tsk It seems maybe you do not (and
let me quote this correctly and attribute it
properly to you) might not know " your butt from a
cabbage" when it comes to reading the literature.

Read a bit more carefully and I will type more
carefully.

>
> One more thing. Using any explo training on UNTRAINED
> athletes may be fine for research but it flat is unethical
> for any strength trainer to perform in real life athletes.
I would agree with that. However, Paavolainen et
al did NOT use untrained subjects. Can an
"athlete" be "untrained" by definition?
(rhetorical, too much time on my hands thought).

[Michael Ro]

On 20 Jul 2002 19:02:36 -0700, bsr3997@my-deja.com (Bruce
Richmond) wrote:

|What appears to be the limiting factor is that not only must
more |force be applied, but it must be done faster.

Bingo

[Stephen Di]

In article <747a5d11.0207201802.349c8174@posting.google.com>,
bsr3997@my-deja.com (Bruce Richmond) wrote:

> Stephen Diamond <stephend15@mindspring.com> wrote in
> message news:<stephend15-D4246A.20284919072002@news.mindsp-
> ring.com>...
> > In article
> > <747a5d11.0207191908.18cd3d8e@posting.google.com>,
> > bsr3997@my-deja.com (Bruce Richmond) wrote:
> >
> > > I suspect the reason for the sub-linear increase is the
> > > angle of the applied force. If the higher force was
> > > applied at the same angle as the lower force, the
> > > vertical component would lift the runner so high that he
> > > would not get back to the ground in time for the next
> > > stride.
> >
> > Which, I think, is another way of saying that the
> > application of increased force is self-limiting; that
> > would make it, prima facie, an unlikely candidate for the
> > most important factor in speed.
> >
>
> Not exactly. The vertical component of the force causes the
> runner to go up, while gravity pulls him back down. His mass
> travels in an arcing trajectory. The height of the arc will
> be the determining factor for the runner's tempo, how many
> strides per minute he can make. He can't start the next
> stride until he gets down. And he had better make that
> stride when he comes down or he will fall on his face.
>
> As I said in the previous post, if more force is applied at
> the same angle, the vertical component is larger, which
> would cause the runner to make long bounding strides. By
> lowering the angle appropriately the height of the arc could
> be reduced to the same as before, and the additional force
> would carry the runner further in the same time as before,
> and at the same tempo. The trajectory of the arc will be
> flatter.
>
> The runner would not need to stretch his stride out to gain
> the speed above. The difference comes from the flight
> distance, when neither of his feet are on the ground. And as
> I said before, the tempo would be the same, so he wouldn't
> have to bring his foot forward for the next step any faster
> than he did before.
>
> What appears to be the limiting factor is that not only must
> more force be applied, but it must be done faster.

I agree with everything up to the last paragraph. Why must it
be done faster? Hadn't you already determined that the tempo
is the same? I think we n