ERS | monograph Introduction: CPET in clinical practice. Recent advances, current challenges and future directions J. Alberto Neder1, Pierantonio Laveneziana2,3, Susan A. Ward4 and Paolo Palange5,6,7,8 This introductory chapter aims to answer three key questions germane to the uses of CPET in respiratory practice. 1) In the past 10 years, what have been the specific scenarios in which CPET has advanced the provision of clinical information valuable to decision making? 2) What are the current challenges facing clinical CPET interpretation? 3) What are the key gaps in knowledge that deserve special attention in the next 10 years in order to expand CPET application in clinical settings? Each of these pertinent questions is answered in the context of the main indications for CPET, i.e. investigation of exercise intolerance and dyspnoea, risk assessment, and outcome evaluation of therapeutic interventions. Background The European Respiratory Society (ERS) has an established track record in producing publications that focus on clinical exercise testing applied to the management of chronic lung diseases. Following the seminal ERS Task Force guidelines published in 1997 [1] and updated in 2007 [2], previous ERS Monographs on Clinical Exercise Testing proved influential in shaping the field [3, 4]. These efforts contributed to the dissemination of the message that, in the appropriate clinical context, CPET does add clinically relevant information. In fact, computerised “metabolic” systems are now available in most advanced pulmonary function laboratories worldwide. As shown in figure 1, 3541 of the 5100 (∼70%) manuscripts involving CPET since 1978 have been published in the past 10 years (Web of Science https://apps.webofknowledge.com). This not only indicates that a new Monograph is timely but that it is also poised to attract a larger readership compared to previous editions. Copyright ©ERS 2018. Print ISBN: 978-1-84984-095-8. Online ISBN: 978-1-84984-096-5. Print ISSN: 2312-508X. Online ISSN: 2312-5098. Correspondence: J. Alberto Neder, Laboratory of Clinical Exercise Physiology, Division of Respirology and Sleep Medicine, Dept of Medicine, Queen’s University and Kingston Health Sciences Centre, 102 Stuart Street, Kingston, ON, Canada K7L 2V6. E-mail: alberto. neder@queensu.ca 1 Laboratory of Clinical Exercise Physiology, Division of Respirology and Sleep Medicine, Dept of Medicine, Queen’s University and Kingston General Hospital, Kingston, ON, Canada. 2 Sorbonne Université, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France. 3 AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l’Exercice et de la Dyspnée du Département ‘R3S’, Paris, France. 4 Human Bio-Energetics Research Centre, Crickhowell, UK. 5 Dept of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy. 6 Chief Internal Medicine and Pulmonary Division, Adult Cystic Fibrosis Program. 7 Policlinico Umberto I Hospital, Rome, Italy. 8 Lorillard-Spencer Foundation, Rome, Italy. x https://doi.org/10.1183/2312508X.10015318