I have had some discomfort on the inside of my right shin. I am guessing a little posterior shin splint or something off balance causing it. If I run 4 miles on pavement then stop it hurts up to 5 days after and then slowly goes away. It is in one location on the tibia and I thought it might be a little stress fracture but if the pain goes away after 5 days then there is really no way to describe it other than a shin splint and myself being paranoid. I am starting to think I need to train on soft ground more often. The only thing is that I worry if running on the beach, is it bad for ankles? I was going to run on this trail and on the beach but want to get anyones input before I go shooting 20 miles down the beach or dirt and not rolling an ankle. So what do you guys think about beach and dirt trail running?