1. A method comprising: selecting, by an athletic activity feedback device, a time-dependent athletic data value from athletic data of a user generated during a completed athletic activity session different from a first athletic activity session; receiving user input defining at least one parameter of the first athletic activity session; determining, by the athletic activity feedback device, a duration of the first athletic activity session based on the at least one parameter and the time-dependent athletic data value; selecting, by the athletic activity feedback device, audible content meeting the determined duration of the first athletic activity session; generating, by the athletic activity feedback device during performance of the user in the first athletic activity session, a first set of athletic data; retrieving, by the athletic activity feedback device, a second set of athletic data corresponding to the first set of athletic data from baseline athletic activity data, wherein the baseline athletic activity data comprises a plurality of sets of athletic data previously generated for athletic activity performed by one of: the user and another user at different times during a second athletic activity session different from the first athletic activity session; and selecting, by the athletic activity feedback device, feedback to output to the user during the first athletic activity session based on a comparison between the first set of athletic data and the second set of athletic data.