What you need to know about Arabians are that they have muscles that are designed for endurance races. They are designed to travel long distances. I think it is Slow Twitch? Don't hold me to that, my equine science teacher would be disappointed in me... The Thoroughbred has a different type of muscle, I believe they were called Type 2. They are designed for shorter and quicker races. So, in a sprint they will beat the Arabian. In an endurance race, the TB wins.