What is your opinion about starting a horse too young or a horse that isn't ready? Many times I see people starting horses that are just past the age of one or sooner, or the horse is extremely underweight. In all truths, I always wait until a horse is 3, even then it depends on the horse. Like for example when it comes to jumping and starting grid work, some people start as early as 2 or 3. And I don't mean some random kid with a pony, an actual trainer. When it comes to that, I like to wait till they're a mature 4 year old or 5. I mean, it just bothers me. Its not fair to the horse at all.