Aims : Body plethysmography allows health professionals to assess functional residual capacity (FRCpleth) and specific airway resistance (sRaw) as primary measures. In combination with deep expirations and inspirations, total lung capacity (TLC) and residual volume (RV) can also be determined. Spiroergometry is a tool for qualitative and quantitative assessment of the cardiocirculatory, pulmonary and metabolic response to exercise. The measurement of oxygen consumption, carbon dioxide production, minute ventilation and heart rate provide substantial diagnostic and prognostic information in a wide variety of clinical settings. This session will provide an overview of when these procedures can be performed (indications and contraindications), will demonstrate how to perform the procedure in the clinic and then discuss how to interpret the results.