If you have a horse who rushes or alters its rhythm after a fence an exercise I find really useful is four cross poles on a circle. Even on an experienced horse there is no need to have the fences at any notable height because this is actually a really strenuous exercise which will require them to really use themselves despite the fences being low. The photos are the height I set it for Fleur who is competing BE Novice, I could have potentially changed the fences to straight bars but the cross gave me a more accurate focal point to ensure I rode an accurate circle.
When setting up this exercise you need to walk your distances to ensure what you are asking of the horse i.e. to maintain a consistent rhythm, is easily possible. I set up the fences on a three stride distance on a curving line between each fence. I am careful to walk the distance on the line I expect to ride from the centre of one fence to the next. With a younger horse if room allows I would far prefer a larger circle so giving 4 strides between fences as it also asks a lot of their balance. If jumping on grass because you don’t have a school large enough consider studs carefully as although the fences are low there is a significant change of slipping on the constant turn.
To start I warm up then canter a circle round and then inside the fences, if your horse can’t easily canter the circle size in the middle with no fences you are always going to struggle to expect them to jump round the larger circle with fences in the way.
If you haven’t ridden this exercise before I would start with poles on the ground between the wings. Go over one pole then around the next then over the next again so riding over the two poles on opposite sides of the circle. Once you are maintaining the rhythm nicely ride over two consecutive poles again repeating then 3 and then finally 4 (or more!).
Introduce the cross poles next firstly one then a second on the opposite side of the circle before introducing the remaining two. Unlike a standard grid which can also be used to regulate the rhythm this exercise can work more effectively as you are working on a constant circle which will help stop the horse fixing its neck or running on after the last element as you get to choose which fence is the last element.
You do have to be careful not to do too much with this exercise and it is best introduced over several days as working from poles on the floor up to crosses will easily tire out even a fit horse plus not only is it demanding on fitness but also on muscle strength.
Finally don’t forget to change the rein regularly so you work an equal amount on both reins.