Reference Values for Cardiopulmonary Exercise Test in Children—How to Report Them Correctly?

Cardiopulmonary exercise testing (CPET) is a gold standard to assess cardiorespiratory fitness (CRF). CRF varied through the lifespan, increasing in children until early adulthood and then gradually declining. Reference values for CPET are used to check whether the child's CRF falls within the normal range. The differences between directly measured and normative age-adjusted exercise data may suggest pathology and are helpful during the diagnostic process. Deriving reference values for children is particularly challenging. Moreover, many children participate in sports, some at an advanced/elite level, which translates into specific adaptations in CPET. The ATS/ACCP statement on CPET presented a checklist that should be followed when reporting reference values. However, the checklist originally focused on adults. This aggravates the quality of reporting pediatric reference values for CPET, making between-studies comparisons difficult. This review (1) presents a step-by-step protocol to fulfill all requirements from the ATS/ACCP statement in the pediatric population, and (2) summarizes the key challenges in deriving reference values for CPET in children, especially among pediatric athletes. Additional recommendations to enrich the quality of reporting reference values for CPET in pediatric athletes were also discussed.