Multidisciplinary treatment of chronic pulmonary insufficiency. 3. The effect of physical training on cardiopulmonary performance in patients with chronic obstructive pulmonary disease.

We examined the effect of physical training on cardiopulmonary function in 21 patients with chronic obstructive pulmonary disease and compared the results with similar observations in eight untrained patients. The training consisted of daily walking on a treadmill at increasing speeds and grades and other graded physical exercises. Evaluation of pulmonary function, including spirometric studies, lung volumes, and arterial blood gas levels, showed no significant change after training. Hemodynamic functions, including heart rate, cardiac index, stroke index, pulmonary vascular resistance, and arteriovenous oxygen content difference, were similarly unchanged at comparable submaximal loads. Pulmonary arterial wedge pressure increased after training in the treated group at rest and during exercise, but this may be related to changes in respiratory mechanics. Consumption of oxygen and minute ventilation decreased in the treated group during treadmill exercise, suggesting improved neuromuscular coordination and efficiency of walking on the treadmill. Total work performed on the treadmill increased significantly in the trained group. This increase was unexplained by physiologic observations but was thought to be due in part to increased efficiency of walking and increased motivation. We conclude that improvement in the capacity for exercise following physical training for four weeks is not associated with improvement in cardiopulmonary function at submaximal exercise.