Physical benefits and challenges of exercise for people with chronic renal disease

Abstract

Objective: To evaluate the physical benefits and challenges of exercise for people with chronic renal disease. Data Synthesis: People with chronic renal failure (CRF or predialysis) or end-stage renal disease (ESRD, requiring dialysis) especially need regular exercise because of the many challenges of renal failure. Physiological limitations contribute to subjective fatigue and reduced exercise tolerance, yet lifestyle factors also play an important role. Forced inactivity required during hemodialysis (HD) treatments, post-dialysis fatigue, and frequent bedrest for illness or surgery all contribute to weakness, stiffness, and sedentary habits. Thus, intentional exercise is needed to resist some of the effects of renal disease and its treatment. Exercise capacity in CRF ESRD is limited by reduced oxygen supply because of anemia and cardiovascular abnormalities. Oxygen supply only partially accounts for a shift from oxidative to glycolytic muscle metabolism. Muscle strength predicts aerobic exercise capacity better than oxygen supply, indicating muscle dysfunction due to other factors. HD may remove some substance needed for normal muscle metabolism. Carnitine supplementation increases exercise tolerance, but the mechanism is not yet understood. Conclusion: Stationary bicycling during HD is safe and effective, makes fluid removal more efficient, and reduces common complaints such as symptomatic hypotensive episodes, chills, muscle cramping, and post-dialysis fatigue. Exercise during HD also provides supervision and encouragement, which improve compliance. In-center and home exercisers should record activity, duration, and intensity. Perceived exertion is a better guide than heart rate for exercise intensity. Patients need to improve strength and flexibility, as well as aerobic endurance.