Home-Based, Moderate-Intensity Exercise Training Using a Metronome Improves the Breathing Pattern and Oxygen Saturation During Exercise in Patients With COPD.

Purpose: One of the well-known but less-investigated effects of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD) is the change in breathing pattern toward a more effi cient one (higher tidal volume [V-T], lower breathing frequency). Evidence suggests this change can be obtained only with supervised, high-intensity exercise training (ExTr). However, some patients either do not have such programs available or are unable to exercise at higher intensity. We evaluated the effects of a 12-wk, moderate-intensity, home-monitored ExTr program using a metronome on the breathing pattern, oxygen saturation (SpO(2)), and dyspnea during exercise in patients with COPD. Methods: Twenty-one patients with COPD (7 female, aged 64-85 yr) performed spirometry, incremental, and endurance walking tests (at 60% of maximal walking speed) on a treadmill before and after training. During the endurance test, patients were equipped with an instrument that continuously monitored ventilation (V-E), breathing pattern, and SpO(2). Patients trained at home for 12 wk, 30 min/d for at least 4 d/wk at moderate intensity. A metronome paced the walking speed. Results: Sixteen patients completed the program. After training, a signifi cant change was observed in breathing pattern (lower V-E and V-E/V-T ratio; P <.001), a higher SpO(2) (P <.001), and a lower dyspnea perception at the same work intensity (P <.01). The V-E/V-T ratio and SpO(2) during exercise were signifi cantly related (r = 0.56, P =.001). Conclusion: A change in breathing pattern towards more effi cient ventilation can be obtained with a moderate, home-monitored ExTr program with a pace that is controlled by a metronome. Decreased V-E /V-T was associated with an improved SpO(2) during exercise.