I keep thinking about this. This past Saturday I had to turn back early from the sat. morning trail run because of the senior class i lead every sat. morning.
Anyway, as I was headed down a very familiar trail on a very clear open section i was able to just clear out the mind and go. I can get to a point where i will run a distance yet no really remember getting there. I no longer feel my feet hit the ground. My breathing gets becomes steady but no labored and although I am looking at my surroundings it seems like i can close my eyes.
I did this three times on sat. then I purposely snapped out of it so I could speed up or hop over one of the streams. This is something i am going to pursue further.