a–f) Respiratory mechanical measurements during incremental cycle exercise in patients with moderate chronic obstructive pulmonary disease (COPD) and age-matched healthy controls. a–f) Respiratory mechanical measurements during incremental cycle exercise in patients with moderate chronic obstructive pulmonary disease (COPD) and age-matched healthy controls. Data are presented as mean±sem. Square symbols represent tidal volume-ventilation inflection points. Pes: oesophageal pressure; Pes,max: maximal Pes; CLdyn: dynamic lung compliance; PEEPi: intrinsic positive end-expiratory pressure. *: p<0.05 COPD versus healthy controls at rest, at standardised work rates or at peak exercise. Reproduced and modified from [17] with permission. Denis E. O'Donnell et al. Eur Respir Rev 2016;25:333-347 ©2016 by European Respiratory Society