Exercise in chronic pulmonary disease: resistance exercise prescription

Resistance exercise training has received relatively little attention as a means to reduce the muscle dysfunction and ensuing exercise intolerance seen in chronic pulmonary diseases. To date, only a few studies have examined the characteristics of skeletal muscle function or its responsiveness to strength training in patients with chronic respiratory diseases. It is clear from these studies, however, that peripheral muscle, particularly muscles of ambulation, are weak in patients with lung disease, exhibiting effort-dependent strength scores that are 70--80% of these measures in age-matched healthy subjects. The degree to which this dysfunction is accounted for by deconditioning, disease-related myopathy, or other causes is unclear. It is evident, however, that patients with chronic respiratory diseases can acquire and maintain substantial improvements in skeletal muscle function, physical function, and quality of life through participation in a well-structured program of resistance exercise training. Despite the positive, albeit limited, evidence that skeletal muscle dysfunction may be improved with resistance training, no clear guidelines are available for this purpose. This review discusses the skeletal muscle dysfunction that accompanies chronic respiratory disease and presents strategies for resistance exercise training that may be considered as part of pulmonary rehabilitation. These strategies are derived from the successful outcomes noted in studies using resistance training in patients with COPD as well as on extrapolations from extant guidelines used to develop strength, power, and endurance in healthy individuals.