Here's a five mile run I do once in a while up here in North Carolina. This was shot on a particularly pretty day.
I'm usually the only person out there at 7 in the morning, so I run for about an hour thinking about what I'm going to write that day, or working on issues in the plot. Sometimes I just watch the trail a few feet in front of me and don't think about a thing. Either way, it's a great run.
Like diving on the same reef, no two days are ever the same. The light, the breeze, the wildlife, all the varying permutations of those things keep the whole experience fresh.