If you ever have the feeling that your canter is lacking power and fragile, then maybe you should try this exercise.
The aim of this exercise is to make the canter adjustable with the horse staying in balance, off the forehand, and responsive to the aids.
Cantering large around the arena, open up the canter down the long side by gently closing the leg. It shouldn’t be rushed, otherwise the horse will fall onto the forehand. At the corner ride forwards to a ten metre circle. If you think of slowing the canter down for the circle you’re likely to overuse the reins and cause the horse to hollow and unbalance.
The circle will collect the canter for you, and bring the hind leg underneath, so engaging the hindquarters and generating a more powerful canter. Initially you may find a ten metre circle too difficult for your horse and they fall out of canter, so ride a twelve metre circle and progress to a smaller circle.
With practice, the canter will extend to medium canter, and condense to collected canter easily and immediately. You should feel that with the adjustability the canter should feel less fragile and stronger. Then the canter should feel more uphill and elevated as the hindquarters engage, which subsequently gives you a powerful canter that is much better for jumping. I’ve used this exercise recently with horses who tend to lose their balance, so that they learn to go forwards from the engine.