Peak symptom-limited incremental treadmill exercise.

Data are presented as mean ± standard deviation. GOLD, Global Initiative for Chronic Obstructive Lung Disease; , oxygen uptake; , carbon dioxide production; , minute ventilation; MBC, maximum breathing capacity; Vt, tidal volume; Fb, breathing frequency; Ti, inspiratory time; Ttot, total respiratory time; Ti/Ttot, inspiratory duty cycle; IC, inspiratory capacity; Δ, change; IRV, inspiratory reserve volume; EELV, end-expiratory lung volumes; SpO2, arterial oxygen saturation measured by pulse oximetry. P-values are from a linear regression model, adjusted for age, sex, alcohol status, employment status, and body mass index. *p<0.05 versus control; **p<0.01 versus control; ***p<0.001 versus control #p<0.05 GOLD 1 versus GOLD 2; ##p<0.01 GOLD 1 versus GOLD 2; ###p<0.001 GOLD 1 versus GOLD 2. †GOLD 2, n = 62.