Abstract: A cardiopulmonary exercise system for real-time, breath-by-breath acquisition, analysis, display and printing of an individual's physiologic parameters. A microprocessor based waveform analyzer receives inputs from a CO.sub.2 analyzer, an ECG monitor, an O.sub.2 analyzer, and a pneumotachograph, and, optionally, can also connect a cycle ergometer, a treadmill, a cardiac stress system, and an ear oximeter. The waveform analyzer provides output data to a host central processor unit to which a CRT display, a graphics copier or hard-copy printer may be connected for providing medical data for assessment of an individual's heart and lungs, on a real-time basis whereby the level of fitness or underlying organic defects which may effect the cardiopulmonary system can be determined. The pneumotachograph, CO.sub.2 analyzer and O.sub.2 analyzer and ECG monitor provide analog signals representing flow, CO.sub.2 and O.sub.2 levels in expired air as well as heart rate.