Supertraining

Hi Paul!
 
In a message dated 6/23/2009 2:07:33 A.M. Central America Standard T,  
[EMAIL PROTECTED] writes:

In a message dated 6/19/09  12:48:19 PM, [EMAIL PROTECTED] 
(mailto:[EMAIL PROTECTED])  writes:

>  We conclude that running on modern, lower-limb sprinting prostheses 
>  appears to
> be physiologically similar, but mechanically different than  running with 
> intact
> limbs.
> 
 
*****
If that is as much as  you can conclude, what do you surmise?
 
Perhaps the IAAF didn't know what they wanted the Cologne group to  
determine, and as it seems from the CAS report,  the Cologne group didn't  know 
what the IAAF really wanted.  At least that's what I gathered from the  final 
report.  Here's part of that report:
 
The Houston Report found that Mr. Pistorius used the same oxygen  amounts 
as able-bodied runners at a sub-maximal running speed, and thus did not  have 
a metabolic advantage. Other tests also showed that Mr. Pistorius fatigued  
normally. Again, the experts agreed that these test results were valid. The 
 Houston Report also tested the amount of energy loss from the Cheetah 
Flex-Foot  prosthesis against the intact human leg, which includes tendons and 
other  elements that generate positive energy(and which, for obvious reasons, 
an  amputated athlete would not have). It is common ground that the Cologne 
Report did not measure any of these elements. In  summary, the Panel 
determines that the IAAF has not met its "on the balance of  probability" 
burden 
of proof that Rule 144.2(e) is contravened by Mr. Pistorius'  use of the 
Cheetah Flex Foot prosthesis for several  reasons.
 
I ask because lower vertical  thrust with comensurate less aerial time 
would 
seemingly require greater  horizontal speed to cover the same distance 
(range) both each stride and  summative displacement.
This in turn implies that greater horizontal thrust  must be delivered by 
the prothesis relative to each stride or at least a  longer impulse to 
effet 
the accelleration from the thrust and this might  be deduced from the 
longer 
ground contact time.
 
Check out figure 1 in the study.  Horizontal 'thrust' is a lot lower  in 
Pistorius.  This goes back to the bouncing ball analogy.  I believe  it was 
also the rationale for not including horizontal forces in JAP 2000.

So then, less metabolic cost  with greater efficiency of motive force in 
the horizontal plane requiring  less aerial time and less swing frequency 
would seem (at firt blush to me  without actually doing the exact figures 
on a 
first approximation) to  argue for a clear advantage to the disadvantaged 
runner. And the 17% lower  metabolic cost seems to indicate the advantage 
is 
best evidenced over the  race of choice, the 400 meters!

It seems as if horizontal efficiency is not a good way to think about these 
 issues since the horizontal work is nearly zero.  If there is pretty close 
 to zero work, then efficiency must be nearly zero as well.  Almost all the 
 metabolic energy is incurred to put forces on the ground.  As a result, I  
don't know if horizontal efficiency is all that meaningful, even if it 
could be  quantified.
 
I surmise the "mechanical  difference" is a mechanical enhancement making 
the racing effort overall  more efficient.
My take on the study is that Pistorius is "cheaper" compared to  other 
sprinters.  However, metabolic power does not limit sprinting  performance, so 
it doesn't seem to matter that much.  What does matter is  stop speed and 
speed at V02max. Pistorius's speed at V02max is right there with  that of the 
intact limb guys.  

What do the researchers think is  suggested by these painstaking 
measurements of the components of the  disadvantaged runner?
I can't speak for the Houston group, but I think we need to look once  
again at the IAAF's "allegations," and why the CAS ruled as it  did.   Another 
CAS passage:
 
"A violation would only occur if the user of the prosthesis gained an  
overall net advantage over other runners, and the IAAF did not ask Prof.  
Bruggemann and his colleagues to make that determination.
The terms of reference put to Prof.  Bruggemann and his team by the IAAF 
did not propose the appropriate  question."
 
It seems to me that the Cologne group was  put in an awkward situation. As 
an outsider trying to look in, I'd say  on this one the IAAF kind of blew  
it.   
 
Ken Jakalski
Lisle High  School
Lisle, IL USA