"that the skin cells change as they are compacted to cells similar to those that create horns, like on an animal".
That is very interesting. My feet are still soft because I moisterize them but thinking about it, I can feel the fat at the bottom of my feet feel firmer.
Since I have started running bare feet, I have found my feet muscles are stronger, I have better coordination of my feet (Maybe because I am not more aware of them from running bare feet) and I can feel my legs are getting much stronger. I can feel my quadriceps have more power(strength) now since I have started running bare feet.
Another notice since I started running bare feet is that I am generally looking after my feet and legs better. I am taking rest days more seriously since I started running bare feet as I don't want to pick up an injury, I also feel more aware of my legs and difference muscles in my legs I never noticed before when I ran with shoes on. I think bare feet running works extra muscles of your legs as well, than running with trainers?