As a white nerdy male, there is an analog that I feel similar to your running scenario. I grew up in the suburbs, more of a sheltered upbringing due to the makeup of the neighborhood. For many years, when I'd be walking downtown, if I saw a group of people that looked like they were from a typical rap video (not specifically any race, but more the group's clothing and body language, although race does play a part of it), I'd turn down another corner. This is mostly due to what got fed to me by TV and other sources, and the knowledge that a nerdy white guy is probably the most hated vulnerable person in that area at that time. Now I know that this is totally irrational, and it wasn't until I forced myself to not turn a different corner each time, that I started to get over it.
Now on another level, I'm a very bashful person, so I have a hard time looking at people in the eyes when I talk to them. Therefore my eyes are pointed at a 30 - 60 degree angle downward towards the floor. And guess what is in that line of site if I happen to be talking to a woman at work? So I learned to just stare straight ahead, or start messing with my phone, whenever a female coworker passes me in the hall. Just to avoid giving the impression that I'm looking her up and down, due to my natural instinct to avoid eye contact by shifting my gaze downward towards the floor after seeing someone make eye contact with me (which, as mentioned, can be taken the wrong way, and land me in HR).
Now on another level, I'm a very bashful person, so I have a hard time looking at people in the eyes when I talk to them. Therefore my eyes are pointed at a 30 - 60 degree angle downward towards the floor. And guess what is in that line of site if I happen to be talking to a woman at work? So I learned to just stare straight ahead, or start messing with my phone, whenever a female coworker passes me in the hall. Just to avoid giving the impression that I'm looking her up and down, due to my natural instinct to avoid eye contact by shifting my gaze downward towards the floor after seeing someone make eye contact with me (which, as mentioned, can be taken the wrong way, and land me in HR).