This simple exercise provides many benefits for both horse and rider, creating more suppleness, starting to engage the inside hind, teaching the light connection to the outside rein and beginning to move away laterally from the rider's inside leg.
A basic spiral exercise can be started once your horse understands how to form a correct circle. The circles don’t need to be perfect, but the rider needs to be able to correct any mistakes well.
The variations for this exercise are many, and you can decide what to do during the exercise depending on how your horse feels. One thing that is important to remember is that if you have planned to do a specific series of movements, but your horse does not feel ready, change your plans for something easier. If your horse feels better than you expected, change your plans to something more advanced!
All variations improve the connection from inside leg to outside rein if ridden correctly.
Diane Followell Classical Dressage Trainer