Newswise — Performing high-intensity weight-lifting exercise during dialysis sessions brings meaningful improvements in muscle mass, strength, quality of life, and other important health outcomes in patients with end-stage renal disease (ESRD), reports a study in the May Journal of the American Society of Nephrology.

"Our findings suggest that patients who regularly perform resistance training exercise during hemodialysis treatment can significantly improve muscle mass, strength, quality of life, and other aspects of health status that are important to people with kidney failure," comments lead author Bobby Cheema, Ph.D., of University of Sydney, Australia. "We believe that exercise should be integrated as standard practice in dialysis units worldwide."

Muscle wasting is extremely common, and one of strongest risk factors for premature death, in patients with ESRD. "Dialysis patients are very inactive in general and commonly burdened by all of the health risks associated with inactivity, particularly type 2 diabetes and cardiovascular disease," says Dr. Cheema.

Dr. Cheema and colleagues studied the effects of progressive resistance training during hemodialysis in 49 patients with ESRD. One group was randomly assigned to perform high-intensity weightlifting exercise—while seated in the dialysis chair—during regular three-times-weekly dialysis sessions. Using equipment such as dumbbells and ankle weights, the patients did supervised exercises targeting all major muscle groups. The exercises were designed to be "hard" to "very hard"—rated 15 to 17 on the widely used 20-point Borg perceived-exertion scale.

By the end of the 12-week study, patients assigned to weight-lifting had improved muscle mass, as shown by measurements on computed tomography (CT) scans. The CT scans showed decreased fat deposits inside the muscles, suggesting the formation of new muscle tissue—an adaptation associated with broad-ranging health benefits, including improved insulin sensitivity and a longer lifespan.

Other benefits of the exercise program included increased muscle strength, improved perceptions of physical functioning and vitality (i.e., quality of life), and reduced pro-inflammatory markers, which are associated with death from cardiovascular disease and other causes. Patients in the weight-lifting group also had increased body weight, further suggestive of an increase in muscle mass, and clinically meaningful improvements in exercise endurance capacity.

All of these benefits were safely achieved with no change in diet, additional physical activity, or other lifestyle factors. "Exercise was carried out safely within the hemodialysis sessions, without any interference with routine care, and no need to change dialysis procedures," says Dr. Cheema. Other studies have shown the benefits of other types of exercise during dialysis, especially stationary exercise cycling.

"Our findings and the findings of previous research, conducted since 1986, have shown that exercise during dialysis is safe and beneficial," says Dr. Cheema. "Unfortunately, at present, very few dialysis units have adopted an active approach to the dialysis procedure. Patients typically watch television or sleep during their 4- to 6-hour, three times weekly dialysis sessions, and this excessive inactivity can accelerate their physical and psychological deterioration."

Dr. Cheema concludes, "Performing regular exercise during dialysis provides an ideal opportunity for these patients to improve their health status and quality of life, and we believe that exercise should be integrated as standard practice in hemodialysis units worldwide. Health care personnel in this setting could easily be trained to carry out supervised weight-lifting exercise, as we have done in this research study."

The study entitled, "Progressive Exercise for Anabolism in Kidney Disease (PEAK): A Randomized Controlled Trial of Resistance Training During Hemodialysis," will be available online at, Media, 2007, beginning on Wednesday, April 4, 2007 and in print in the May issue of the Journal of the American Society of Nephrology.

The American Society of Nephrology (ASN) is a not-for-profit organization of 9,500 physicians and scientists dedicated to the study of nephrology and committed to providing a forum for the promulgation of information regarding the latest research and clinical findings on kidney diseases.