As for some other breeds--many of the gaited breeds
were originally bred to cover ground comfortably and do it all day. While
their gaited-ness may interfere with speed, many have at least reasonable
metabolic traits for this sport. So what's a person's particular
goal? Some of these horses make pretty good mileage horses, some are even
somewhat competitive, and while like all breeds (Arabs included) there have been
traits bred for the modern show ring that are not conducive to endurance, if one
finds the individuals that are of a previously popular working type in most
gaited breeds, one has a pretty reasonable shot at endurance.
The Standardbred is probably second only to the
Arab in the percentages within the breed suitable for our sport. While
they've been bred for the track, the trotters have been raced rather differently
than the TB's in that they run several heats in one day, and hence have
maintained some pretty reasonable metabolic traits for endurance as well.
Biggest disadvantage to Standardbreds, IMO, is that they tend to have only one
gear at the trot--LONG--and can be kind of funny to look at from the vet's
viewpoint, unless the rider can really RUN to present them, and get them going
fast enough that those legs get into gear! <g>