Re: RC: RC: endurance prospect

[Tivers@aol.com]

In a message dated 2/5/00 3:27:40 PM Pacific Standard Time, 
rides2far@juno.com writes:

<< O.K.  tell me if I'm way off base, but I know the 2 types that excelled
 in 50's and 100's respectively were basically lean, fast cooling machines
 for 50's and horses with more substance and reserves for 100's.   >>

My guess is that it's going to be a bigger animal for all distances in races 
like the UAE races where most of the terrain is relatively flat. The 
rider/horse weight ratios have a significant effect, particularly in the 
longer races--so you need some mass. The small agile horses are going to be 
more useful in the hills, but you don't want to get too small, as long as 
there is a minimum weight rule. 

Running "cool" is going to have a lot to do with the fuels being burned and 
with the muscle fiber types burning them. But a low-rev engine is also going 
to be a gigantic factor. In time, one of the criteria for purchasing 
prospects is going to be left ventricle diameter and contractile fraction, 
measured via ultrasound. You'll want a heart that can rev on command, but 
never has to during a strong lope on the flat. 

Capillary and mitochondria density will be major factors, and are trainable. 
You can deal with a higher FT/ST fiber type ratio, as far as body temp is 
concerned, if you have capillary density.  In order to achieve this 
additional aerobic "surface area" you're going to have to train at higher 
heartrates than most currently believe useful. 

ti