Are clydesdale horses a fast horse for running?

Yes I think that they would be a fast horse for running. For more information search for the question how fast is a clydesdale horse. They have some pretty good information.

2nd answer:

Clydesdales are bred for power - pulling plows, freight wagons, and so forth. The smaller, sleeker horses like the Arab, thoroughbred, and the quarter horse run much faster than the Clydesdale.