ABSTRACT
RATIONALE: Exercise-induced dynamic hyperinflation contributes to decreased exercise tolerance in chronic obstructive pulmonary disease (COPD). It is unknown whether respiratory retraining (ventilation-feedback [VF] training) can affect exercise-induced dynamic hyperinflation and increase exercise tolerance. OBJECTIVES: To determine whether patients with COPD would achieve longer exercise duration if randomized to a combination of exercise training plus VF training than either form of training on its own. METHODS: A total of 64 patients randomized to 1 of 3 groups: VF plus exercise (n = 22), exercise alone (n = 20), and VF alone (n = 22). MEASUREMENTS AND MAIN RESULTS: Exercise duration before and after 36 training sessions and exercise-induced dynamic hyperinflation and respiratory pattern before and after training were measured. In the 49 patients who completed training, duration of constant work-rate exercise was 40.0 (+/- 20.4) minutes (mean +/- SD) with VF plus exercise, 31.5 (+/- 17.3) minutes with exercise alone, and 16.1 (+/- 19.3) minutes with VF alone. Exercise duration was longer in VF plus exercise than in VF alone (P < 0.0001), but did not reach predetermined statistical significance when VF plus exercise was compared with exercise alone (P = 0.022) (because of multiple comparisons, P
Subject(s)
Biofeedback, Psychology/methods , Breathing Exercises , Exercise Therapy/methods , Exercise Tolerance/physiology , Pulmonary Disease, Chronic Obstructive/rehabilitation , Respiratory Therapy/methods , Aged , Bicycling , Exercise Test , Hospitals, Veterans , Humans , Middle Aged , WalkingABSTRACT
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(+EX)), exercise only (EX(ONLY)), or ventilation-feedback only (VF(ONLY)). 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(+EX), EX(ONLY) and VF(ONLY) groups, respectively. The VF(ONLY) 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(+EX) group, and in f and Te in the EX(ONLY) group. After completing the training, VF(+EX) and EX(ONLY) patients reported less breathlessness and perceived exertion (p < 0.05). The VF(ONLY) patients' ratings changed in the hypothesized direction but were not significant. Based on these preliminary data, VF(+EX) and EX(ONLY) were equally effective in improving leg-cycle exercise tolerance in patients with moderate to severe COPD.
