TY - JOUR T1 - On the issue of exercise normalcy JF - European Respiratory Journal JO - Eur Respir J SP - 286 LP - 287 DO - 10.1183/09031936.00030809 VL - 34 IS - 1 AU - J. A. Neder Y1 - 2009/07/01 UR - http://erj.ersjournals.com/content/34/1/286.abstract N2 - To the Editors: Cardiopulmonary exercise testing (CPET) has evolved as a useful tool for evaluation of exercise capacity in apparently healthy subjects. In the clinical arena, CPET is widely used to judge exercise “normalcy” in individuals with a suspected disorder and patients with several potential causes of exercise limitation 1. In order to establish “abnormality”, however, it is crucial to obtain representative frames of reference to interpret the (lack of) appropriateness of the systemic responses to exertion. Unfortunately, this is not a trivial task in the nonathletic subject as there are multiple confounding factors, especially behavioural characteristics such as the level of regular physical activity. Not surprisingly, there are only a few sets of reference values for clinical CPET interpretation which have survived the proof of time and are currently used worldwide 1. In this context, the study recently published in the European Respiratory Journal by Koch et al. 2 is welcomed. After evaluating a large sample of apparently healthy … ER -