Figure 3.

Acute effects of bronchodilation therapy on operational volume during constant work rate cycle ergometry in patients with COPD.

Notes: Example of operating lung volumes during constant work rate cycle ergometry performed at 75% maximal workload after dosing of placebo (gray symbols) or bronchodilation therapy (black symbols). Adapted with permission from the American College of Chest Physicians. Maltais F, Hamilton A, Marciniuk D, et al. Improvements in symptom-limited exercise performance over 8 h with once-daily tiotropium in patients with COPD. Chest. 2005;128(3):1168–1178.¹⁵⁰

Abbreviations: COPD, chronic obstructive pulmonary disease; EELV, end-expiratory lung volume; IC, inspiratory capacity; IRV, inspiratory reserve volume; TLC, total lung capacity; V_T, tidal volume.