Ummm...Romeo did a running walk, a fox trot, and a canter for the majority
of the Joe Tate 100 miler. We did some trotting, but not much...In fact,
at 100s where I was willing to let him trot more (like Tevis) we were
pulled...JME. As far a hollow backed...He won't travel if his back is
hollow, not for any distance. That's why saddle fit has always been fun
with him (well, OK, because with his very short back, many saddles DON'T fit,
and he immediately does either a hard trot or a hard pace until the thing is
taken off his back).
This is an interesting question. Since my best horse 6 100's
out of 7 was gaited with the Arab not having a 100 in him (my judgement
but I know him) but still going strong at 19 I've thought about it often.
First - and this probably won't be popular - I'm not sure there any
horse out there except maybe Remington that can gait 100 miles and I
think he trotted a good bit. Bruce might join in on this. I let the
mare do what ever gait she wanted and it was pretty much split between a
nice long and low smooth trot, easy canter to hand gallop and a very
fast walk. She would throw in a running walk every once in awhile but it
was not the primary her gait of choice.
I think that gaited horses
even if they trot they don't have as much suspension and probably don't
have the mechanical wear and tear as a trotting horse might just
because of the suspension. However, it takes energy to go 100 miles or 50
miles independent of gait. At least in my experience I was a lot less
tired riding the mare than I am the Arab so in that respect - I was
probably easier on her which sapped less of her energy to compensate of
the rider.
As far as lateral gaits many tend to be hollow backed - that
can't be good over the long
run.