Thanks for comments, here is a link to the article I was reading. Natural Hoof - Articles: On Track
We are thinking of doing a track around ten acres to try and give the paddocks time to rest. I also liked the idea of the horses putting in the extra miles. It's quite steep land, so I'm hoping the chest muscles may get a good work out.
I have also thought of maybe putting in some points of interest around the track poles, logs to step over that kind of thing.