It was two chapters long, IIRC. In it, Faith had felt that merely Running had lost its thrill, and found a community of Runners in the same boat and had turned to having sex in dangerous positions and places. The first chapter had her with a man, and the second with a woman, and I vividly remember that for these hook-ups, Faith decided to use the assumed name of Ms. Danvers.
If anybody can locate it, I would greatly appreciate it.