Model utility in the study of cardiorespiratory control.

This study investigates the utility of differing modeling approaches to the study of cardiorespiratory control. Models are classified in terms of intended purpose. A structural model predicts behavior based on a hypothetical physiological structure. An empirical model summarizes observed behavior. A functional model attempts to relate physiological structure to observed behavior. Models from the literature for exercising man illustrate these concepts and motivate the importance of experimental design in terms of the dynamic variation of a work-rate input.