Effect of an unsupervised walking program on tolerance to exercise in patients with chronic obstructive pulmonary disease.

Abstract

Chronic obstructive pulmonary disease (COPD) is a preventable disease characterized by persistent respiratory symptoms and airflow limitation that is usually caused by the exposure to harmful particles, mainly tobacco smoke (1). In the course of the disease, lung function deteriorates, exercise tolerance decreases and quality of life worsens. All these factors contribute to an increased risk of death. Exercise intolerance measured with a 6-minute walk test (6MWT) is a powerful indicator of health deterioration and a predictor of prognosis (2). An increase of 30 meters in this test is considered the minimal clinically relevant distance to consider effective any intervention (3). This test assesses disability as well as the effectiveness of pulmonary rehabilitation (4).