Sports require and build fitness: muscle strength, balance, flexibility, agility and overall body awareness. Even after a short ride, non-riders will notice certain muscles will be quite sore. Riding requires a few muscles that aren't often used in other sports. The control it takes to use rein, leg and seat aids to influence a horse requires refined body awareness somewhat similar to a gymnast. While it's not necessary to be a body builder to ride, dealing with an animal many times larger than yourself does require some physical presence.

Mental Exercise

Skill, strategy, reasoning, memory and confidence are required in most sports, and it is no different for riding. Memorizing dressage tests and jump courses, following trail maps, choosing the safest route on a trail ride, deciding the most effective way to handle a horse that is acting up (that sometimes requires split-second timing) and always being aware of what your horse is thinking is mental exercise.