Never, Never, Walk alone! Always have at least one partner, be aware of
your surroundings at all times, look, listen and do not become
complacent, carry a cell phone in case of emergency and always report
anything suspicious, immediately. Do not put yourself in harm’s way if
you witness something inappropriate. It’s important to be confident,
loud and not willing to be a victim of any crime.
So while the reasons as to why these naked men are running (and in one case, masturbating) remain a mystery for the moment, it can probably be narrowed down to one of a couple of different reasons:
1. Chased by chupacabra!
2. Sometimes it's fun to run naked in the woods.