Don't forget Charge Cindy, a quarter horse,
won the Old Dominion 100 at least a couple of times in the 70s. In
spite of the fact that we didn't know much about elytes, beet pulp, and whatever
else one uses now, Charge Cindy did that tough ride in a pretty fast time.
She was an awesome horse. So quarter horses can do the job with the proper
conditioning, smart riding. Some are built better for distance than others
so will handle the longer distances better.
Jeanie