I don't know what to think about it but I seem to run into these people every once in awhile. I'm running along and I come up to someone walking either coming up to them from behind or in front to where they can see me. As soon as they either hear me coming up from behind them or see me approach them, they start running. Is it coincidence? I haven't really seen any runners in the trails that I run so I'm kinda of thinking thinking that they are just casual walkers. But why break into a run when they see someone running?