The importance of exercise training in rehabilitation of patients with end-stage renal disease.

Exercise capacity in patients with kidney failure undergoing dialysis is low compared with age-predicted values. The level of exercise tolerance in these patients is such that the energy requirements for activities of daily living and occupational tasks impinge on their capacity to perform these tasks. Therefore, it is not surprising that many patients do not seek or are unable to work because they are physically unable to sustain the energy required for such activity. There are several ways to increase exercise tolerance in these patients--transplant, exercise training, and recombinant human erythropoietin (epoetin) therapy. Successful kidney transplant increases exercise capacity to near normal values for sedentary healthy individuals. Exercise training after transplant further increases exercise capacity and counteracts some of the negative side effects of glucocorticoid therapy, such as muscle wasting and excessive weight gain. Exercise training in patients on dialysis increases exercise tolerance approximately 25% (in studies performed before epoetin administration). Similar increases are observed after correction of the anemia of kidney failure with epoetin. However, the increase in exercise capacity is small compared with the magnitude of change in hematocrit level. It is possible that epoetin therapy unmasks a muscle limitation to exercise that may be improved by exercise training. Anecdotal evidence suggests that exercise training in patients on epoetin therapy may result in an exercise capacity similar to that of transplant recipients. However, epoetin therapy to improve hematocrit levels does not automatically make patients exercise. Active counseling and encouragement are necessary to improve physical functioning.(ABSTRACT TRUNCATED AT 250 WORDS)