How do I lengthen at a trot and canter?

Lengthening at the trot and canter — asking the horse to increase his stride length and ground cover while maintaining the same rhythm and tempo rather than simply going faster — is one of the most fundamental and most revealing exercises in all of riding. A horse that genuinely lengthens covers more ground with each stride because his hind legs are reaching further under his body and his front legs are swinging further forward in response to increased hindquarter thrust — not because he is running faster with shorter quicker strides but because each stride is covering more ground at the same tempo the working gait established. The prerequisite for genuine lengthening is genuine collection, and this is counterintuitive enough that many riders miss it entirely. Collection is not a separate exercise for advanced horses — it is the compressed organized energy that lengthening releases forward, and without some degree of collection the horse has no energy stored to release into the lengthened stride. A horse working in a flat running on-the-forehand working trot cannot produce a genuine lengthened trot because the energy that lengthening requires is not available in that working state — asking for more simply produces more speed rather than more stride. The aid for the lengthened trot is applied at a specific moment in the stride cycle rather than generally throughout multiple strides. The most effective moment to apply the lengthening aid at the trot is during the rising phase of the posting trot — as you rise, the horse's inside hind leg is leaving the ground and swinging forward, and the leg aid applied at this moment asks that swinging hind leg to reach further forward in its arc than the working trot required. The simultaneous opening of the hand at this moment — allowing it to soften and yield slightly forward — gives the energy that the leg has created somewhere to go rather than blocking it against a closed hand. At the canter the lengthening aid is applied during the moment of thrust from the outside hind — the first beat of the canter stride — when applying leg asks the outside hind to push more powerfully and reach further under the body in its propulsive phase. The seat in a canter lengthening should be following and driving rather than deep and containing — the rider should feel herself being carried forward by the horse's increased thrust rather than absorbing it into a collecting seat that would counteract the lengthening aid. Transitions between working and lengthened gaits are the gymnastic tool that develops the horse's ability to lengthen over multiple sessions. Work across a diagonal in lengthened trot, transition to working trot at the corner, re-establish the collection for a few strides, ask for the lengthening again on the next diagonal. The quality of the transitions into and out of the lengthening is as important as the quality of the lengthening itself, because the ability to collect immediately after lengthening and lengthen immediately from collection is what distinguishes genuine elastic gaits from a horse that can run faster when pushed but cannot organize the transition between compression and extension without losing rhythm or balance.