AUTHOR=Neder J. Alberto , Phillips Devin B. , Marillier Mathieu , Bernard Anne-Catherine , Berton Danilo C. , O’Donnell Denis E. TITLE=Clinical Interpretation of Cardiopulmonary Exercise Testing: Current Pitfalls and Limitations JOURNAL=Frontiers in Physiology VOLUME=Volume 12 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.552000 DOI=10.3389/fphys.2021.552000 ISSN=1664-042X ABSTRACT=Cardiopulmonary exercise testing (CPET) remains largely underused in clinical practice. Apart from operational aspects (e.g., high equipment costs, limited availability, poor reimbursement relative to time spent on testing performance and interpretation), there are several shortcomings on its interpretation which have shed a negative light on CPET as applied to pulmonology. We herein provide a concise perspective on some key contemporary issues, including: a) over-reliance on rigid interpretative algorithms, b) incorrect display of graphical data, c) underestimation of dyspnea assessment, d) misinterpretation of a “preserved” peak O2 uptake as evidence of normality, e) lack of appreciation of the confounding effects of obesity, f) failure to recognize the poor diagnostic performance of CPET in indicating cardiac disease, g) misdiagnosis of mechanical-ventilatory limitation, h) overlook of the limitations of non-invasive assessment of pulmonary gas exchange, and i) over- and under-call of a chaotic breathing pattern and dysfunctional breathing in dyspneic subjects.