I used to think that people who ran on the street were somehow Suspicious because I associated running with escaping from emergencies. For example, you run away from fire or from a crime scene. And also who would run in the rain?! or when it is hot.
I had that thought way back in the past when I was a child and crises could happen anywhere in anytime. Now, I still associate running with escaping but in a good healthy way as it is an outlet to release your negativity and absorpt the positivity from the natural surroundings.