Limitations of exercise reconditioning in COLD.

T his comment by Alvan Barach in 1951 emphasizes the -relative ignorance that existed only three decades ago concerning the “reconditioning” of patients with chronic obstructive lung disease (COLD). Dr. Barach’s proposal to exercise patients with disorders of oxygen transport met with appropriate skepticism in the clinical community. Until well into the 1960s, the standard therapy for patients with COLD was rest and avoidance of stress. The first study to question this dogma directly was published in 1962, when Pierce et al2 demonstrated what has since become dogma in 1982; reconditioning patients with COLD permits them to perform the same exercise with lower heart rate, respiratory rate, minute ventilation, and CO2 production. These benefits were obtained without change in pulmonary function and the authors wondered whether they were due to increased efficiency of motion, or to enhanced oxygen utilization within exercising muscles. Two years later, Paez et al concluded that efficiency and oxygen utilization were both improved. Christie4 then demonstrated that these changes could be achieved on an out-patient basis with relatively little supervision. The past 15 years have witnessed a virtual explosion in the investigation and popularity of exercise therapy. Many patients with COLD are now automatically placed in a pulmonary rehabilitation program, or encouraged to recondition themselves with judicious activity. A number of recent reviews have addressed the specific goals and techniques of exercise reconditioning and its proposed benefits. 9 This review will concentrate on the limitations and uncertainties of this mode of therapy. PROPOSED BENEFITS