Fig. 1From: Mechanisms affecting exercise ventilatory inefficiency-airflow obstruction relationship in male patients with chronic obstructive pulmonary diseaseFlow diagram. A total of 120 male patients with chronic obstructive pulmonary disease were enrolled after excluding nine subjects aged 80 ≥ years. 118 participants completed the lung function test and 46 patients, the subgroup, completed arterial blood gas analysis during exerciseBack to article page