Turns out it was 4 more miles. No big deal. Picked up a couple bottles of the Diet Coke with Splenda, chugged one, and headed back north (railroad west). I was tired when I got back to the car, but really, I think I have more pain from the root canal (and that's almost none).
Also discovered a neighbor from one street down using the trail. He was gone when I got back. I guess he isn't hard core ;)