Thoraco-abdominal motion/displacement does not affect dyspnea following exercise training in COPD patients

Purpose: The interrelations among chest wall kinematics (displacement and configuration), ventilatory profile and dyspnea relief following cycle exercise training (EXT) have not been systematically evaluated in hyperinflated chronic obstructive pulmonary disease (COPD) patients. We hypothesize that a decrease in ventilation affects dyspnea relief, regardless of the changes in chest wall kinematics. Methods: Fourteen patients were studied before and after 24-session exercise training program. We evaluated the volumes of chest wall and its compartments (rib cage, and abdomen) using optoelectronic plethysmography. Results: At iso-time EXT (i) reduced ventilation, respiratory frequency and dyspnea (by Borg scale), mildly improved rib cage configuration, but left operational volumes unchanged; (ii) Borg was much smaller for any comparable inspiratory reserve volume (IRVcw), and a decrease in IRVcw was tolerated much better for any given Borg. Conclusions: Regardless of the changes in chest wall kinematics, a decrease in ventilation attenuates dyspnea following EXT.