Re: RC: Re: Discrete Inquiry

[Tivers@aol.com]

In a message dated 7/14/00 7:18:43 AM Pacific Daylight Time, Onefarmgirl 
writes:

<< << One of the primary adaptations seen in longterm endurance conditioning 
is greatly increased mitochondrial use of intramuscular triglycerides. 
Virtually all of the fat used during endurance competition in humans comes 
from this already-stored and efficiently-converted substrate source.  Little, 
if any, fat in circulation is used as racing fuel when carbohydrate 
supplementation is being used during the race. And, of course, adipose tissue 
is the most costly of fuels to mobilize. >>
 
 I presume this entire graph applies to humans?  If so, using it as a 
springboard for the subsequent theory w/o validating applicability to equines 
seems to me to start you off with one foot in a bucket.   Or perhaps the 
human-equine similarities/differences in cellular energy production are 
already quite well understood?   If not, it seems you'd need to do that 
first, or proceed with much caution, since as we have seen, tiny differences 
(one enzyme) can make big differences in species.   A substance or regimen 
which is useful in one species can 
 be harmful in others.>

Human exercise/nutritional research doesn't arise in a vacuum. These types of 
muscle energy partition studies have been done in most living animals--cows, 
sheep, pigs, rabbits, insects, birds, horses, camels. All mammalian muscle 
uses the same substrates--there are only a few--in essentially the same way, 
from the same sources. One mammal may have an advantage or disadvantage in 
processing one type of macronutrient over another--but the end products are 
the same, and the muscles use them in the same way. 
 
 >Along that same vein, even if we 'know' that the celluar energy physiology 
is the same, I think you may be making a leap about dietary supplementation 
and how it supports the substrate base.  Equine digestive processes are so 
very different from our own, that timing food sources to manipulate this 
system may likewise be different.>

Agreed. That's why you perform field trials. You could attempt to duplicate 
all that has been done in laboratory research in humans, but that would 
require decades--and there just isn't the funding. So, field trials, similar 
to what happens on the human side between coach and athlete, are the 
solution. In human athletics you take whatever advantages you can with this 
information and win with them--let the physiologists follow up when they have 
time. 

And sometimes you run into problems, as we did when we were intially loading 
rcehorses. Turned out that timing on race day was critical--and we didn't 
know that. You can't run a racehorse on a low or crashing blood glucose--you 
get a "flat" race. Took us two years to figure that out, because of all the 
drugs these horses get on a routine basis--too many variables to quickly sort 
out in the field. But, we learned. Same way we're learning in endurance. 
Trial and error.  
 
 >I guess I was a bit confused by what information in your post is data that 
you know, and which is information you are seeking to validate (or not).  For 
instance, do we know that this information>

What we know: 1) carb supplementation during an endurance ride, timed 
properly, produces the same beneficial effect seen in human endurance 
athletes. 2) without alresdy-stored substrates available in quantity, carb 
supplementation doesn't do much good in races beyond 80K. 3) carb loading in 
the endurance horse confers further advantage, but can deliver a very 
enthusiastic horse at the start--this can be a two-pronged disadvantage--a 
horse that is hard to control and/or a horse that builds body temp too 
quickly. Doesn't always produce those disadvantages, though--so refining the 
technique might be useful. 4) other than muscle and liver glycogen, the 
primary stored substrate in mammals is intramucular triglycerides, and 
ensuring that these are stacked away prior to the event will be an advantage. 
5) Endurance conditioning results in many benefits, among them increased 
capillary density and mitochondrial density--maing the delivery and 
conversion of IMTGs very efficient--in all mammals. 

Those are some of the things we KNOW. What we don't know is the best protocol 
to maximize the benefits and minimize any negatives that might arise from the 
protocol I laid out--for example, loading fat can be a problem in a number of 
ways, beginning with digestive upset and ending with free-radical damage and 
possible ketosis. Thus far, I am not suggesting anything that has not already 
been done in the horse.  
 
   
  >"That underlying triglyceride substrate base is the key to never having to 
worry about available substrate under a carb-supplemented high-output 
competition." 
 
 applies to equines, or is that part of the theory you are advancing?>

Yes   
 
 
 >My other area of concern would be more pragmatic, and it's reflected in 
your question
 
 <<  How does a shift to a primarily carb-based training diet to a fat 
loading diet affect digestion?  >>
 
 In general the digestive processes of the equine are relatively easy to 
disturb.  Humans seem to be iron guts in comparison.   The varied dietary 
tweaking thay you suggest may have unforseen consequences in gut motility or 
nutrient absorption and transport, even if they are useful in energy 
production and availability.>

Correct. However, changes in feed types that I've witnessed in the real 
world, including here on Ridecamp, have often gone far beyond what I am 
suggesting, with apparently no ill effect. For example, horses have been put 
on 15% fat loading diets for 6 weeks with no ill effects. And I've told you 
how much carbo-feeding has been done with no ill effect. So, we have some 
parameters already established. I don't propose to go beyond those 
parameters. My proposal is more an ordering of macronutrient intake with the 
final stages of conditioning and competition.  
  
 << And that's why I'm asking you to wrestle with this concept a little in 
your spare time.>>
  
 Happy to wrestle with the concept, unable to contribute to 'field trials' 
with my one endurance horse  :-)>

Good enough

ti
 
 
 pat farmer
  >>