Fig. 1
From: Practical guide to cardiopulmonary exercise testing in adults
Principles of exercise physiology. The characteristic changes in key variables of ventilation, cardiocirculation and pulmonary gas exchange during progressive exercise are shown. Anaerobic threshold (AT) documents the transition to mixed aerobic-anaerobic metabolism, respiratory compensation point (RCP) documents the transition to predominant anaerobic metabolism. A more detailed description of Fig. 1 can be found in Additional file 1 (see Supplementary Information)