Systems and methods for monitoring and/or assessing metabolic and/or cardiopulmonary parameters of a subject are disclosed. Systems and methods for high speed monitoring of metabolic parameters of a subject in a substantially unrestricted setting are disclosed. Further disclosed are wearable systems and methods for substantially unobtrusive monitoring of a breath stream from a subject. Also disclosed are wearable systems and methods for real-time monitoring of the respiratory function and/or one or more disease states of a subject. Data systems to coordinate simultaneous monitoring of one or more metabolic and/or cardiopulmonary parameters of a plurality of subjects are also disclosed.
