【Objectives】 To study the correlation between dynamic hyperinflation (DH) and exercise capacity in patients with chronic obstructive pulmonary disease (COPD). 【Methods】 Routine lung ventilation function

diffusing function

lung volume and an incremental symptom-limited cycle ergometer exercise were tested in 26 stable COPD patients and 12 healthy controls. Flow-volume curve during tidal breathing and inspiratory capacity (IC) were detected every 1 min at rest and exercise. 【Results】 The IC (L) was significantly lower in COPD patients at peak exercise than at rest(1.55 ± 0.46 vs 2.17 ± 0.50

P < 0.001). The ΔIC was negatively correlated with the peak oxygen consumption in COPD patients (r = -0.422

P < 0.05). The peak IC was negatively correlated with both resting IC (r = -0.743

P < 0.001) and peak VT (r =-0.755

P < 0.001) in COPD patients. 【Conclusions】 DH might be one of the important factors for exercise intolerance in stable COPD patients during incremental symptom-limited cycle exercise.