ridecamp@endurance.net: Fats, glycogen, creatine loads, doo dah doo dah...

Fats, glycogen, creatine loads, doo dah doo dah...

Susan F. Evans (suendavid@worldnet.att.net)
Thu, 24 Apr 1997 08:53:15 -0700

Hi Tom!

> Anyway, Susan. Life's short. Let's get into some good stuff--talk about fat:
> My racehorse guys tell me that they see a couple of weeks of benefit in
> performance and then the horses lose their edge, then, gradually, a lot of
> their speed. this, in my mind is due to an increasing muscular dependance on
> fat and a storing of lipolytic enzymes in preference over glycolytic enzymes.
> So I'm telling my folks to get off the high fat feeds (anything over 12%).

I agree. I went and looked up some studies both in humans and horses
and found out some pretty nifty stuff, including one unpublished study
done by the military trying to turn already-world-class marathon
athletes into Super distance runners by feeding them---are you ready for
this---an 80% fat diet!!! No typos, eight oh percent. The Navy's coy
tap-dancing around trying to politely describe the fact that these poor
slobs had the trots like the flooding of the Nile is absolutely
hysterical to read. However, once you're done giggling about the
semantics (OK, so I'm easy to entertain), there is some pretty
interesting take-home information on what the almost-exclusive reliance
on fats as a fuel source did to their endocrine glucose homeostasis
systems and anaerobic capacities.

However, I have two killer midterms tomorrow and I MUST get out the
door, so forgive if I rudely push this off until the weekend until I can
discuss it fully. However, the short answer is, I agree with you 100%
that high fat is great for endurance horses, but a VERY poor choice for
TB and SB. Assuming that those trainer's aim is theoretically to get
the horses to do a better job of Go Fast Turn Left.

> They tell me that burning fat is also oxygen--expensive compared to carbs and
> produces higher body temps. Is this true?

Yes, and by the way, not only is it true, but I owe you a public apology
over this one. Some months ago, you made this statement and I rather
snippily disagreed. I was absolutely wrong. My class notes did show
the numbers as carbos requiriing more O2 to burn than fat, but my notes
were incorrect, which I found out very recently. Geez, what an airhead!
Fats contain more total energy per gram than carbos, but carbos are
indeed more efficiently burned based on O2 consumption---which logically
makes sense, considering that carbos are the fuel of choice (actually
only fuel) in anaerobic conditions.

So my apologies for the blunder. I gotta start taping the lectures and
checking my notes afterwards to counteract the Airhead Effect.

> Finally, assuming that in high speed race horses the glycogen loading process
> is as effective as I'm saying it is. Why would it be more effective than in
> human athletes?

Personally, I don't know except that I know horses already contain more
glycogen in their muscles than do humans under "normal" conditions. And
some animals (like whales and seals) store even more to supply the fuel
for hour-long dives---if you've ever seen fresh whale muscle, it's
almost black with myoglobin.

However, I did corner one of my professors, with a bright and shiny
new Ph.D and very bright guy who also works as a trainer for
world-class track and field athletes, very motivated to find out Real
Answers and as of yet, no big pressures from Administration to publish
the politically correct results so as not to tick off King
Such-and-such, etc. (it happens, at least around here, on occasion. A
long story.) Although he has little experience with horses, he was
intrigued and promised to go look through his library (better than mine)
and call up some of his old profs. Will let you know what he says.
Both of us agreed that where research gets fun is when you get to 1)
Identify Effect, 2) Identify Pathway of Effect and 3) Try to Manipulate
Pathway to Get Better Effect.
Good stuff.

And why would creatine loading have no effect at all in
> horses?

Darn. I was going to ask you about whether you'd tried creatine
loading. No effect at all? You'd think it would. Sure works wonders
in humans. May I ask at what dosage and what the loading protocol was?
I'd like to show it to some people around here and see what their
thoughts are. Creatine loading research in humans is moving so damn
fast that you can hardly keep up with it and maybe there's something new
that just popped up that could refine a protocol for horses.

When you tried it, did you attempt any lab analysis of muscle fibers, or
did you just observe overall performance? Would like to know.

One more question for you---what would be your estimate of how fast a TB
reaches anaerobic threshold during a race? I would assume pretty
quickly if he's working hard and it's a relatively short distance (as in
less than an endurance horse). And how about for the SB's? Same or a
bit slower to hit AT?

Talk to ya soon, gotta get going to the Study Dungeon. See y'all this

Susan Evans

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