Re: RC: Re: First treadmill carb test.

[David LeBlanc <dleblanc@mindspring.com>]

At 10:33 PM 12/26/99 -0800, GESA BRINKS wrote:
>Tom, please do keep us up on the treadmill testing.  I thorougly enjoyed it
>and am waiting for more results.     gesa n clovis
>-----Original Message-----
>From: Tivers@aol.com <Tivers@aol.com>
>To: ridecamp@endurance.net <ridecamp@endurance.net>
>Date: Sunday, December 26, 1999 1:52 PM
>Subject: RC: First treadmill carb test.
>
>
>>Beth gave me the information necessary to use our V02/VC02 expired gas
>>machine on the treamill and we conducted our first test of it this morning.
>>
>>We worked a horse submaximally for 4 hours on the treadmill, watching the
>>V)2/VCO2 ratio every 10 seconds. From what Beth tells me, a ratio of 1.0 or
>>higher indicates 100% carb metabolism. Dips below 1.0 indicate increasing
>use
>>of fat as fuel.

I don't know how you derive that.  What you're basically measuring is how
well the lungs absorb O2 and expel CO2.  If the blood is well-saturated
with O2, you'd expect to see lower transfer of O2.  There's also some
effect on the fluid dynamics of the lung from respiratory rate - lower
rates would tend to reduce the surface area, which also reduces transfer.

How you get from that to what is getting burned isn't clear to me.

>>At 30 seconds into the exercise, the ratio was .17--mostly fat metabolism.

No, you've just still got the blood saturated with O2 as you'd expect from
a resting start.

>At
>>40 seconds into the work, the ratio crossed 1.0 and seldom dipped below
>>thereafter. Periodically there were 10-20 minute periods where it hit as
>low
>>as .89, but that situation seemed to correct itself reasonably quickly.
>>
>>This horse was not carb supplemented and the work level was low--no
>>heartrates above 125. We just wanted to see if there was a trigger point
>for
>>a switch to fat metabolism. There were a couple of minor ones, but nothing
>>significant. Unless, Beth, those couple of 10-second intervals where the
>>ratio hit .89 were significant--you tell me.

No telling - be interesting to find out.


David LeBlanc
dleblanc@mindspring.com


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