Effect of resistance exercise during hemodialysis on physical function and quality of life: randomized controlled trial.

AIMS: The objective of this study was to determine whether 24 weeks resistance training during hemodialysis could improve exercise capacity, muscle strength, physical functioning and health-related quality of life compared to a low intensity aerobic program. MATERIAL AND METHODS: 27 patients (55.6 +/- 17.6 years) were recruited from two hemodialysis clinics in Valencia (Spain). Patients were randomized to resistance training (n = 19) or low-intensity aerobic training (n = 8). Resistance training consisted of three sets of 4 exercises at an intensity of 12 - 15 out of 20 at the rate of perceived exertion scale (Borg scale measuring self-rated exercise intensity) using weights and elastic bands on every session during 24 weeks. Primary outcomes included physical performance tests, evaluated by the "sit-to-stand-to-sit tests" and the 6 minutes walking test, and knee extensor muscles strength, evaluated by isometric dynamometry. Secondary outcomes included cardiorespiratory fitness, measured by time and METs (measure of energy expenditure as ml of oxygen per kg of weight and per minute; 1 MET is equal to 3.5 ml O(2)/kg/min) achieved on a graded exercise test, and quality of life, measured by the SF-36 questionnaire. RESULTS: No differences were noted in change-over-time between the two groups in any of the physical performance tests. However, a significant change was found in change-over-time in right knee extensor muscles dynamometry, and intragroup analysis showed a significant improvement in resistance training groups in the physical performance tests and METs. CONCLUSIONS: These findings suggest that resistance training during hemodialysis improves patient's physical functioning.