My little horse has a very long, VERY LONG history of adults riding.
The Icelandic was never bred as a chlild's riding pony, it was bred for adults to ride.
In Iceland there is no choice, the Icelandic is the only breed, if you are a man of 6 foot 6inches and 250lbs or a child of 3 you ride an Icelandic!
I do not do 50 mile endurance rides on Ljóssie. I do no more than 2 hour rides at most, I do mostly flat work and competition gait work with him.
I would never have chosen, by choice, such a small horse for my personal competition horse normally, but he came to me as a bit of an accident. He is so nervous and sensetive that his old owner was having mega problems with him. I rode him once and the pair of us clicked, I assure you he has no problem carrying me.
There is a very great deal of difference with modern breeds and ancient ones. Icelandics have a far higher bone density than other modern breeds.
I have ridden Shetland ponies of no more than 38 inches.. cruel?... no. A Shetland bred Shetland is up to the job.
Please don't dismiss a horse of short stature as being a kiddies pony, there is no way I'd let anyone ride Ljóssie that was not a VERY, VERY accomplished, quiet, sympathetic, balanced, kind rider, it's taken me 3 years to make him trust me, if he was in any pain or discomfort I'd still be having trouble. The Icelandic I have offers Tölt, trot, pace canter gallop and walk freely, he can keep pace with a horse of 15 hands with me riding him. He can perform all the basic dressage moves in walk, trot, tölt and canter without rushing or panic. I get shoulder in, leg yeild, counter canter and the odd decent flying change. He's happy, I'm more than happy.
Yes in the eyes of the mainstream horse world I am traditionally too big for him but who is the judge of that, is it the onlooker or the horse?