Longeing is not a cure-all, but it can be helpful in releasing some of the excess energy of a tense horse. However, the original use for longeing was not as a means of tiring the animal, but of training it. Traditionally, longeing has been used to accustom young horses to working under tack and to improve the balance and rhythm of horses of all ages. If the longe line is gradually shortened so that the horse is brought onto a smaller circle, the exercise will teach the horse to collect itself. The smaller circle is more stressful on the horse's body, however, and should only be maintained for one or two revolutions before the animal is allowed to return to the original track.
When the horse's equipment is adjusted properly and the person longeing the animal keeps it going forward in a steady rhythm at each gait, longeing correctly develops the horse's haunches and topline. Four five-minute sessions, with a change of direction between each, is plenty of work on the longe line for normal training. With a tense horse, it may take another ten minutes, but if you longe longer than this you are risking lameness. Longeing is confining, and the same physical stress that quiets the tense horse can break it down if used to excess.