Exercise duration rather than peak oxygen uptake better correlates with Fev(1) and inspiratory capacity in chronic obstructive pulmonary disease

Background. Exercise duration of constant-load endurance tests has been recently demonstrated to be more sensitive in detecting the changes after bronchodilator administration than either walking distance or peak oxygen uptake in patients with COPD. In the present study, we questioned whether exercise duration of progressive load is better correlated with forced expiratory volume in 1 sec and inspiratory capacity than other indices of submaximal exercise test during stable period in patients with COPD