Highly educated older horses are called "Professors". These very experienced school horses have a lot of education to pass on to the rider and can teach a rider for example to ride in a side saddle. On the picture you see the wonderful "Professor" Patrovinia, a Russian mare and former horse of Hanna Engström.
Older Olympians bring experience to the Games - CNN.com
Who says an Olympic athlete has to be young to be spry? Seventy-one-year-old Hiroshi Hoketsu, competing for Japan in dressage -- a choreographed equestrian exercise that shows off a horse rider's command of their horse -- is the oldest competitor at the London Olympics.
Something to keep in mind when you lunge your horse. Fixed headsets, fixed postures, fixed gaits for long or even short stretches of times do not build fitness, instead they build stiffness. Too much energy/activity runs the horse down and damages its body. Not enough energy/activity and he becomes careless and indifferent....(more below)