Trotting is a diagonal two beat horse gait which comes in a number of flavors. A horse's speed at the trot is between a walk and a canter, and this gait is very energy-efficient, which means that horses can sustain a trot for long periods of time. Novice riders are typically introduced to the trot at a very early stage, since it is necessary to learn to work with a horse at the trot before riders can proceed to faster gaits like the canter, or advanced riding skills like jumping.
When a horse trots, two legs move forward at the same time and pause for a moment before the other two legs are brought forward. This gait is diagonal, which means that one foreleg and the opposite hind leg are moved forward together while a horse is trotting, in contrast with lateral gaits, in which two legs on the same side move together. The trot creates the distinctive “clip clop” sound many people associate with horses in motion.
There are three basic types of trotting: collected, working, and extended. When a horse moves in a collected trot, the body is kept very compact, the strides are short, and the legs are raised high. The collected trot is often on display in the dressage ring, because it reflects a very controlled horse and showcases the power in the hindquarters. In a working trot, the horse exhibits a natural stride length; most horses can demonstrate a working trot naturally, without requiring additional training.
The extended trot involves more extension of the legs, with the horse taking strides which are as large as possible while not breaking into a canter. In harness racing, horses are run at the extended trot with their necks outstretched to the full; horses may also keep their heads up in an extended trot, especially in the show ring, and this gait gives horses a very rounded appearance.
There are numerous variations on trotting gaits. The collected trot, for example, is the basis for a piaffe, a trot in place displayed in dressage rings, and the passage, a collected trot which moves in slow motion. Racehorses are often worked out at the jog trot, a variation of the working trot.
There are a number of ways to sit a horse while it is trotting. Beginning riders typically learn posting, which involves moving up and down in the saddle with the gait. Remaining fully seated allows for greater control over the horse, but it also requires strength on the part of the rider, since sitting a trot can strain the muscles of the lower back and leg. Some riders also use a half-raised seat, which offers minimal control but sometimes greater comfort.