Abstract: A system including a metabolic rate monitor can monitor one or more metabolic determinants to determine a user's metabolic rate. An interval identifier can detect a plurality of intervals corresponding to a least one type of user activity over a time period, wherein each of the plurality of intervals is employed to record the user's metabolic rate determined by the metabolic rate monitor. A metabolic adaptation calculator can determine an adaptation of the user's metabolic rate based on analyzing the user's metabolic rate over each of the plurality of intervals. A recommendation module can provide an output indicating at least one of the metabolic determinants to adjust in response to determined adaptation.