The Impact of Yoga on Inspiratory Muscle Performance in Veterans with COPD: A Pilot Study

Chronic obstructive pulmonary disease (COPD) causes respiratory muscle weakness that leads to disabling dyspnea and poor functional performance. Therapies are often geared to improve inspiratory muscle performance. Yoga has been shown to improve exercise capacity, quality of life, and some pulmonary function measures in COPD, but little research has examined the effects of yoga training on inspiratory muscle performance. The purpose of this study was to investigate the effects of yoga training on inspiratory muscle performance in military veterans using the Test of Incremental Respiratory Endurance (TIRE). A prospective pilot study examined a 6-week yoga training program consisting of asana (poses) and pranayama (controlled breathing). Subjects had baseline inspiratory muscle weakness. The TIRE measured inspiratory muscle performance via the PrO2 device, providing maximal inspiratory pressure, sustained maximal inspiratory pressure, and inspiratory duration. Secondary measures included 6-minute walk distance, St. George Respiratory Questionnaire, Hospital Anxiety and Depression Scale, and spirometry. Mean age and BMI of subjects were 67 ± 3.6 years and 20.7 ± 3.3, respectively. The majority of subjects had severe (28.7%) or very severe (57.1%) COPD. Statistically significant improve m e n t s were seen in maximal inspiratory pressure (39.0 ± 14.1 cmH2O to 56.4 ± 20.6 cmH2O) and sustained maximal inspiratory pressure (244.1 ± 100.6 PTU to 308.1 ± 121.2 PTU). No statistically significant improvements we re observed in 6-minute walk distance, St. George Respiratory Questionnaire, Hospital Anxiety and Depression Scale, or spirometry. Yoga training has the potential in improve inspiratory muscle performance in veterans with severe to very severe COPD who present with inspiratory muscle weakness. This is of importance because improving inspira-tory muscle performance has been shown to improve COPD outcomes.