Another one here in the absolutely no headphones camp. It is bad enough that I am a lone female out biking/running as it is. I don't need an mp3 player on to make me look more of a victim to any potential assclown who thinks he can try something because he thinks I am distracted by my music.

I ride/run to listen to my body and to get outdoors. I need to hear my breathing, the rhythmic thump of my feet on the ground, the ratcheting of a freewheel, the wind in my face, the burn in my quads. Music plays a large part in my life, I love it. But not when it could put me in a potentially dangerous situation.