<< On Sun, 22 Dec 1996 23:28:41 -0500 Tivers@aol.com writes:
>Here's the logic of it: it is known that fat requires far more oxygen
>per
>unit of energy than does glycogen. Oxygen at the muscle cell site
>requires
>oxygen delivery. Oxygen delivery requires heart muscle activity. A
>higher
>oxygen demand requires a higher heartrate.
>
>ti
>
>
Tom,
Wouldn't more RBC's do the trick without raising the HR? Is fat burning
something that can be conditioned?
Lindavan
>>
Well, your horse carries a "backpack of endurance" in the red cells he has
sequestered in his spleen, and, with intense exercise that periodically
causes these red cells to be injected into the bloodstream, splenic capacity
increases siginificantly--up to 50% OF RED CELLS can be sequestered in the
spleen in very fit horses. But to cause the spleen to contract, a pretty
serious quarter mile of speed is necessary. At least in race horses. About
half of these extra red cells will be resequestered in about 30 minutes. So,
if you want quick heartrate recovery, fifteen minutes before stopping for a
rest, a little burst of speed might help. However, I have no idea what
percentage of red cells remains sequestered in an endurance horse after a
long ride.
The way to find out: take a blood sample for PCV before exercising the horse.
Do a hill workout and take another sample. You will have ejected most of the
red cells with that work. The difference between the two PCVs will give you
an idea of the percentage sequestered. Then you can do a before and after
with typical endurance activity and compare those results with the first.
Yes, fat burning can be conditined as well. But that involves the muscle
cells storing more lipolytic enzymes instead of glycolytic enzymes. I don't
know if that's a good idea.
ti