Science engine operative to select workout segments responsive to user-supplied information about their physical state

A tangible, non-transitory, machine-readable medium storing instructions that when executed by one or more processors effectuate operations comprising:

• receiving, with one or more processors, via a network, a request for a workout from a user computing device, the request identifying a user account stored in memory and associated with a user;
• in response to the request, accessing, with one or more processors, a fitness plan associated with the user account and a requested fitness focus, wherein:
• the fitness plan is selected based on a fitness goal of the user;
• the fitness plan includes a sequence of workouts;
• the user account indicates a current state of the fitness plan including a next workout in the sequence of workouts and previous user feedback on at least part of at least some past workouts in the sequence of workouts;
• future workouts in the sequence of workouts are partially, but not fully, specified by the fitness plan and each future workout corresponds to a plurality of candidate workouts, each of the candidate workouts partially, but not fully, specifying a plurality of exercises;
• and
• the candidate workouts are each associated with a different fitness focus;
• selecting, with one or more processors, a workout from among candidate workouts of the next workout in the sequence of workouts of the fitness plan associated with the user account based on the requested fitness focus and respective fitness foci of the candidate workouts of the next workout;
• accessing, with one or more processors, descriptions of exercise in the selected workout;
• and
• providing, with one or more processors, via a network, the descriptions of exercises to the user computing device for presentation in a sequence specified, at least in part, by the selected working.