A short film is making the rounds this week; I've seen multiple sources sharing it. Basically, a crew set out in a UK park with a camera and a cart of some sort. They tooled around the bike paths looking for runners, and interviewed them as they ran.
One of the reasons running is so appealing is that it is akin to therapy. Problems can be solved on runs. I've long held that this is because of the increase in blood flow, and the resulting increase in oxygen delivered to your brain. Like an oxygen bar, the effects cease when the activity stops.
The runners in this film are ordinary people, but they all have one thing in common: they seem to be at peace with their places in the world.