Shorten and lengthen the rein

When I am preparing to transition from trot to canter, I shorten my reins. At that point, Princess tends to rush forward into a fast trot. This is not what I want, so I thought I would spend some time just in trot, shortening and lengthening my reins. The aim of the exercise is for her to realise that shorter rein does not always mean canter, and she should stay relaxed.

I am trotting. I shorten the rein. Princess rushes forward. I ask her to slow back down to the trot we had a second ago. And here, the use of the reins becomes clear. Outside rein to control rhythm and tempo, inside rein to ask for flexion. Outside rein acts first, and continues acting, saying slow down. Inside rein acts second and intermittently asks "look inside the circle". Outside leg determines the size of the circle, inside leg says "bring the hind leg underneath". The outside aids are constant. The inside aids are intermittent.

The minute I have a nice soft horse on this really short rein, I lengthen the rein again. The trot largely stays the same, although possibly more engaged. This proves to be a superb exercise. We repeat it three or four times. It actually feels like fun! By the third or fourth time, the horse no longer rushes forward when I take up the rein. I ask for canter and get a very responsive transition, and a superb quality canter.