Reduced skeletal muscle endurance and ventilatory efficiency during exercise in adult smokers without airflow obstruction.

Smokers without airflow obstruction have reduced exercise capacity, but the underlying physiological mechanisms are not fully understood. We aimed to compare quadriceps function assessed using nonvolitional measures and ventilatory requirements during exercise, between smokers without airway obstruction and never-smoker controls. Adult smokers ( = 20) and never-smoker controls ( = 16) aged 25-50 yr with normal spirometry, underwent incremental cycle cardiopulmonary exercise testing to exhaustion with measurement of symptoms and dynamic lung volumes.

Exercise response to oxygen supplementation is not associated with survival in hypoxemic patients with obstructive lung disease.

Purpose: Hypoxemia is associated with more severe lung disease and worse outcomes. In some patients with chronic obstructive lung diseases who desaturate on exertion, supplemental oxygen improves exercise capacity. The clinical significance of this exercise response to oxygen supplementation is not known.

Pulmonary Gas Exchange Abnormalities in Mild Chronic Obstructive Pulmonary Disease. Implications for Dyspnea and Exercise Intolerance.

Rationale: Several studies in mild chronic obstructive pulmonary disease (COPD) have shown a higher than normal ventilatory equivalent for carbon dioxide ([Formula: see text]e/[Formula: see text]co2) during exercise. Our objective was to examine pulmonary gas exchange abnormalities and the mechanisms of high [Formula: see text]e/[Formula: see text]co2 in mild COPD and its impact on dyspnea and exercise intolerance.

Methods: Twenty-two subjects (11 patients with GOLD [Global Initiative for Chronic Obstructive Lung Disease] grade 1B COPD, 11 age-matched healthy control subjects) undertook physiological testing and a symptom-limited incremental cycle exercise test with arterial blood gas collection.