Why are horses rideble?

Answer 1

Horses have to be "broken in". This is when you train them to take a rider's weight, ware a harness, saddle, etc. I think some of the first people to ride horses were the Red Indian's, but they rode bareback (without a saddle).

Answer 2

Horses aren't born rideable. When they are young they are broken in by their owner or trainer. It's a long process that can take many months. The way many trainers break in their horses is by first desensitizing their horses to 'scary objects,' and by letting their horses get used to having a saddle on their backs before they actually hop on them. The trainer will gradually increase the training for the horse. So maybe for the first few weeks the horse will be led around with saddle, then next comes the bridle, then after a while they will sit on top of the the horse to get him used to the feeling, and later on they will teach the horse to properly walk, trot, canter and so on. After a young horse has had it's basic training he is called a "green" horse,(not the color) which means the horse has learnt the basics but still needs to be trained more, like teaching him to do lead changes, jumping, side passes, shoulder-in's, and/or piaffes. Usually, the older and more trained a horse is, the easier it is to ride. A 18 year old lesson horse would be a piece of cake to ride, rather than riding a hot, 5 year old green broke horse. :)