I just started my horse in hunter. He's never jumped before and we're taking it slowly, working with ground poles and 18" cross rails. Soon we'll try a 2'. I've read in different places that for the sake of the horse's legs, you should really only jump 1-2 times a week. Would that also apply when training a horse to jump? He is an ex-race horse, but 100% sound. He's 10. I'm hoping if he continued to do well we can try showing this summer, but while he learns -very- quickly, I don't want to overwork him nor go less than he can handle. Thoughts?