An update on clinical recommendations for cardiopulmonary exercise testing in children with respiratory diseases

Introduction: Cardiopulmonary exercise testing (CPET) is a diagnostic-integrated tool for evaluating cardiovascular, ventilatory, and metabolic functional limitations in children with respiratory diseases. Recently, novel applications have emerged, revealing dynamic abnormalities that may go unnoticed in standard static cardiac and pulmonary function tests. Given its clinical importance and novel research findings, updated recommendations are warranted. Areas covered: We conducted a narrative review based on a literature search up to April 2025. This review provides an update on the application of CPET in pediatric respiratory diseases, covering physiological differences to adults, non-traditional CPET metrics such as the oxygen uptake efficiency slope (OUES), tidal volume to inspiratory time ratio (VT/Ti), and recent reference values. Indications, contraindications, and standardized protocols are discussed, alongside emerging trends in CPET technology. Expert opinion: CPET is a potent tool for assessing, evaluating, and diagnosing pediatric respiratory diseases. Standardized protocols, age-specific reference values, and novel CPET parameters enhance clinical utility. Future research should refine interpretation, integrate artificial intelligence for data analysis, and facilitate CPET for younger children.