The purpose of this study was to evaluate the efficacy of a unique program of ventilation-feedback training combined with leg-cycle exercise to improve exertional endurance and decrease perceived dyspnea in patients with chronic obstructive pulmonary disease (COPD). Thirty-nine patients (67.5 ± 8.1 yr of age) with moderate to severe COPD (42.6% of predicted forced expiratory volume in 1 s) were randomized to one of three 6-week experimental interventions: ventilation-feedback with exercise (V[sup+EX]), exercise only (EX[supONLY]), or ventilation-feedback only (VF[supONLY]). At baseline and at 6 weeks, patients completed a constant work-rate leg-cycle ergometer test at 85 percent of maximal power output. There were increases within the groups in exercise duration: 11.5 min (103%), 8.0 min (66%), and 0.4 min (4%) for the VF[sup+EX], EX[supONLY], and VF[supONLY] groups, respectively. The VF[supONLY] group experienced no significant within-group changes in selected gas exchange parameters. However, there were significant (p < 0.05) posttraining changes in minute ventilation, tidal volume, breathing frequency (f). and expiratory time (Te) in the VF[sup+EX] group, and in f and Te in the EX[supONLY] group. After completing the training, VF[sub+EX] and EX[supONLY] patients reported less breathlessness and perceived exertion (p < 0.05). The VF[supONLY] patients' ratings changed in the hypothesized direction but were not significant. Based on these preliminary data, VF[sup+EX] and EX[supONLY] were equally effective in improving leg-cycle exercise tolerance in patients with moderate to severe COPD. [ABSTRACT FROM AUTHOR]