I gave a couple of horses and riders a good gymnastic workout a few weeks ago.
It was a grid of 3 bounces, followed by one stride to an upright and then two strides to an oxer.
The three bounces encourage the horse to be neat with their legs and quick over the fences, and he needs to be gymnastically very supple and fit to be able to do the three bounces successfully.
However, after the third jump, the horse needs to travel with a good length canter stride in order to reach the bigger upright. If a horse finds the bounces physically challenging then they tend to struggle to make the distance to the upright, and end up chipping in. Then, the horse has a larger oxer to negotiate, when they are starting to tire. The upright jump requires a similar shapes bascule as the bounces, but the oxer requires the horse to take off slightly further away and make a longer bascule so that the horse clears both the front and back rail of the oxer. The change in bascule over the fence is physically demanding of the horse, so requires a high degree of suppleness and gymnastic ability.
However, because the bounce fences have improved the quality of the bascule and encouraged the horse to engage their abdominals and “round” the canter strides so improving their cadence the horse will usually make a more correct shape over the larger two fences and feel more confident over the bigger jumps. The pony in the video below is only 14hh and before Christmas found 80cm jumps tricky, and frequently chipped in before jumps, but the oxer here is just over 1m and he cleared it comfortably and confidently, as well as keeping a very good, positive canter throughout the exercise. If anything, he makes the jump look small.
I did this exercise with a horse who tends to get very long in the canter while jumping. The bounces improved his technique and made him shorten his canter, which meant that over the last two fences he didn’t get so close and had enough time to tuck up his forelegs.
In a smaller arena a few days later, I took out the upright fence in order to fit the grid in, which actually made the exercise a bit harder because there was no gradual lengthening to the canter and bascule. Instead, the 14.2hh horse has to go from a short, neat pop over the bounces to a longer, bigger fence which involves a bigger adjustment to their body so requires more suppleness. This little horse managed the exercise really well, and due to the bounces improving her canter she cleared 1.10m in a very neat and confident way.