ABSTRACT
AIM: to analyze respiratory and peripheral neuromuscular efficiency during exercise in COPD. METHODS: COPD patients (VEF1 = 39.25 ± 13.1 %) were paired with healthy subjects. It was performed cardiopulmonary exercise test with simultaneously electromyography (EMG). Respiratory neuromuscular efficiency was determined by relationship between tidal volume and diaphragm EMG. Peripheral neuromuscular efficiency was determined by relationship between power output and vastus lateralis EMG. RESULTS: Healthy subjects presented higher respiratory neuromuscular efficiency at moderate, heavy and maximum exercise intensities compared to COPD (p < 0.05). Healthy subjects presented higher peripheral neuromuscular efficiency at light, moderate, heavy and maximum exercise intensities compared to COPD (p < 0.001). Dynamic hyperinflation presented correlation with respiratory and peripheral neuromuscular efficiency (r = -0.73 and r = -0.76, p < 0.001). CONCLUSION: COPD patients have lower respiratory neuromuscular efficiency at moderate exercise intensity and lower peripheral neuromuscular efficiency at light exercise intensity. Dynamic hyperinflation affects respiratory and peripheral neuromuscular efficiency.