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your answers only confuse me. So, you are telling me that you are using a model that doesn't allow any internal losses to be the basis for calculating real world internal losses using inverse dynamics?
You're right, the way that I stated it was confusing. What I should have said was that that hypothetical scenario has been repeatedly presented so that you will understand how the sources of various losses can be quantified (using inverse dynamics). Specifically, by recognizing that - in the absence of friction, limb bending, etc. - there is absolutely no energy lost in the interconversion of potential and kinetic energy, you would now be in a position to apply this correct understanding of the fundamental physics to the in vivo situation. However, despite your grudging acknowledgement that you have been wrong all along regarding the basic physics ("...for the sake of the present discussion..."), I still don't think you really get it.
Again, how do you use a system that prohibits limb bending (or soft tissue deformation) to evaluate a system that does. One can eliminate friction, or material deformation, or anything else, in the model if one wants to try to isolate the various areas of loss. But, isolating an effect requires that effect be kept in the model. It seems unreasonable to use a model that eliminate every possibility of loss to try to examine the magnitude of the various losses that the 2nd law dictate must be there. Using such a model dictates you get an answer (zero losses) that violates the second law (even though your starting point may not. No one, except me, seems to have noticed this little "problem."
The purpose of modeling is to help one better understand the real world. Using an unsuitable model, as you and everyone else has here, has simply made everyone's understanding worse because it has come up with an answer that cannot be true (it didn't look at anything "real world") and violates a fundamental law of thermodynamics and yet, "everyone" insists it is right.
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Exactly how is that done?
Force pedal measurements + high speed film + knowledge of basic physics = ability to quantify the power "flow" through the ergometer + rider system. What such measurements reveal is that there is very little inefficiency "downstream" of when the limbs are set in motion - rather, essentially all of the inefficiency arises "upstream".
Very little is not zero. And, the data of McDonald suggests there are substantial losses, the unloaded losses are almost 300 watts under certain conditions. The smallest losses they encountered was about 70. You, and everyone else, have had to go through all sorts of mental gymnastics to make the data fit your unsuitable model (loading the chain suddenly makes the losses go away). It is bizarre to me that you would still be supporting this model for determining internal losses.
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Exactly which physiological data did I insist on dragging into the discussion that is making it impossible to differentiate this stuff?
Martin's.
Ugh, which data is that?
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Frank,
An original Ironman and the Inventor of PowerCranks