"Café de Colombia" <
[email protected]> wrote in message
news:[email protected]...
> Phil Holman wrote:
>
> >
> > We tend not to argue with it but try to understand why it doesn't apply
to
> > everyone.
> >
> > Phil Holman
>
> You people,
>
> It's not going to do any good trying to "understand" it when all these
"studies" are erroneously reducing the
> biomechanical ergonomics and physiology of the cyclists' legs as being
defined by leg length.
>
> Citing studies that assume that everyone who is a certain height or has a
certain leg length has the same muscle
> insertions, tendon attachments, underlying physiology, etc. of their leg
introduces huge error factors. The fact is,
> there is tremendous variation in absolute strength, speed, wattage output,
and endurance of people with the SAME leg
> length that would allow certain riders of the same leg length to do better
using DIFFERENT crank arm lengths.
>
> I don't see where any of these studies make a distinction between the leg
physiology of a 6'0" marathoner verses a 6'0"
> sprinter with identical leg lengths. All these studies would seem to end
up recommending the same crank arm length
> based merely on equal leg length.
>
> Consequently, all of these studies are far more flawed than you think, and
not just because Mr. Zinn forgot to allow
> for adpatation to take place.
>
> The reality is the best crank arm length for a rider must be measured
individually, and cannot ever be extrapolated
> from studies done on other people. Even if you did mean wattage output of
many cyclists with the same leg length, the
> result would be off for any given rider who might be at the extreme end of
the bell curve and would therefore benefit
> more from using a correspondingly extreme crank arm length.
>
> Carl Lewis would likely benefit from using a different crank arm length
and cadence than a marathoner of identical leg
> length. To assume he should use the same crank arm length as a marathoner
just because they both have the same leg
> length is clueless.
>
> So you people are trying to fit square pegs in round holes when you make
one of the variables "leg length" instead of
> leg physiology and leg ergonomics.
>
> You people aren't that smart after all,
And apparently neither are you: in studying maximal power, Jim in fact did find weak but significant
correlations between optimal crank length and leg or tibia length. Perhaps these correlations would
have been greater had if actual muscle lengths been used. *However, that would not change the fact
the effects of crank length on maximal power were trivial at best.* IOW, a given rider generated
essentially the same maximal power on cranks that varied markedly in length. Since their muscle
lengths didn't change, that means there is little *functional* relationship between muscle length,
crank length, and maximal power, regardless of how you express the data. Indeed, this is exactly
what you would expect, given that the force-length relationship of muscle shows a broad plateau at
the sarcomeric level.
Now tell me something new, Cafe' de Crackhead,
Andy Coggan
