I had been riding for about 6 years until a few years ago when I stopped. I was starting in Eventing competitions jumping about 3 ft. I am trying to get back into it again and was wondering what ground exercises would be fastest and most affective in gaining back some muscle? I have pretty good upper body positition right now and would like to focus mostly on my legs.....Also I cannot get to a gym. If anyone has suggestions that would be great!