1. An athletic performance control system, comprising: a display system that presents workout information to a user, wherein the workout information includes information relating to content of a user's workout routine; a user interface system that prompts the user for a first input relating to a desired workout intensity parameter for the workout routine, wherein the user interface system prompts the user for the first input after the workout routine has begun; an input system for receiving the first input; and a processing system programmed and adapted to provide, under at least some circumstances, a revised or modified workout routine based, at least in part, on the first input.