 From doctoral referral and advertisement, 24 obese BMI 27 kgm2 and 26 lean post-menopausal women were recruited for the study. Pulmonary function and body composition were measured at rest. A maximal flow volume loop MFVL was obtained at baseline. All subjects then performed an incremental exercise test on a cycle ergometer with workload increasing 25 watts every 3 min. During exercise, at each workload, the tidal exercise FV loops were obtained and an inspiratory capacity IC maneuver was conducted to assess changes in end-expiratory lung volume EELV and end inspiratory lung volume EILV. Dyspnea and leg fatigue were assessed using the Borg scale. Analysis of variance with repeated measurements was used to test the significance of the mean differences between the two groups during exercise. Linear regression analysis was used to determine whether changes in dynamic lung volumes during exercise were related to changes in Borg scores. Statistical significance was established at p0.05. 