Hi Teddy
Sorry, maybe I'm not understanding what you mean? No flames, just would
like to know. I am QUITE sure of my information here (God knows, spent
enough time in class getting it drummed into my head <g>), and I'm not
disputing what's in Tom's book, maybe we're all just saying the same
thing and putting different labels on it. However, if you want, you can
check out any biochemistry or exercise physiology book to check out what
I'm saying---the result of 1 molecule of glucose or glycogen entering
the glycolytic cycle is 2 ATP, plus 2 pyruvic acid, which are converted
to 2 (less toxic) lactate molecules. 2 lactate molecules plus some
energy input is either converted in the liver back into one glucose
molecule; OR 2 lactates can be oxidized back into pyruvic acid and
either then converted into glucose/glycogen and/or can enter the TCA
cycle and go through the aerobic cycle that way, producing more ATP; OR,
it can be excreted via urine and sweat as a waste product if there's too
much of it around at that particular moment for the body to deal with.
My point is is that lactates ARE a fuel, always, always, always,
that also just happen to be a metabolic by-product. You don't have to
"train" anything to burn it, because it already does that. Always has,
always will. Any muscle/hepatic system does in almost any species I can
think of, not just horses, let alone just race horses. There are things
about the glycolytic cycle that can be affected by training, but that's
not one of them, because that is lactate's Purpose in Life. Really. No
offense, (and REALLY, I mean that!) I'd be happy to copy the chapters
out of my textbooks to save you the trouble of digging out a biochem
textbook.
But I would be interested to hear Tom's opinions/discussion/point of
view on training horses to burn lactates. As far as I know, a system
can be trained to tolerate higher concentrations of lactates before
disruption and can be conditioned for higher anaerobic efficiency by
increasing the mechanisms and enzymes that support the glycolytic cycle,
and so on, lactates are always recycled as a fuel source.
Thanks for the post, Teddy :->
Susan Evans
Equine Research Center
Cal Poly University