Not much that we do with horses is "natural" but for some jumping is what they love to do. I know with my guy if I turn him out in a ring with jumps he will start making his own courses. And having a fabulous time of it. And when you're on him and jumping it's the only time he actually has energy and rather than constantly pushing him you have to hold him back. So with some it's what they have been breed to do and what they really enjoy.

As for how hard jumping is on them. Yes it can be hard on them but if you are careful and treat them right you can have a solid jumper for many years. Most of the top grand prix horses are around 15 and still going strong. We have one at our barn who is just about 20 and still doing grand prix's. And he was campaigned pretty hard in europe for most of his life. Even went to the olympics as a alternate horse.