Systems and methods for prescribing athletic activity to be performed by a user, and for adapting the prescribed athletic activity based on completed (e.g. ongoing) athletic performances by the user. A coaching plan may be automatically created that prescribes personalized athletic activities as a user trains towards a goal date. The athletic information may be received from one or more sensor devices associated with a user, and the coaching plan may be continuously or intermittently updated based on the received sensor data.