I have been running/walking barefoot alot. I actually always barefoot everywhere all the time. I've been trying to get my feet toughened for pavement. It seems like the bottoms of my feet are always tender when running on pavement or concrete? It seems like they don't ever toughen up to a point where they don't feel raw? I can gravel trail run and dirt trail run just fine with no problem, but it seems like pavement keeps my feet tender feeling, kinda a stinging feeling on the forefoot but tender? What is this and does it ever get any better, or is it just one of those things that goes along with barefoot running?