Effects of regular resistance training on muscle histopathology and morphometry in elderly patients with chronic kidney disease

Objective: To evaluate muscle histopathological outcomes, adaptation in muscle fiber area, and fiber type proportion after a resistance training program for patients with chronic kidney disease. Design: Vastus lateralis muscle biopsies before and after the study period in seven patients and six healthy subjects performing the exercise program and in five patients in a nonexercising comparison group. Results: The change in degree of histopathological abnormality did not differ between the groups after the exercise program. Muscle fiber type proportion and muscle fiber area was also the same after the observation period. Conclusions: Patients with chronic kidney disease have muscle histopathological abnormalities already in the predialysis phase. There was no indication that the exercise program had disadvantageous effects on muscle histopathology in these patients. There were no differences in muscle fiber area or in fiber type proportion after the exercise program within or between the groups. Thus, a workload of 60% of one repetition maximum was sufficient to increase muscular strength and endurance in patients with chronic kidney disease but not to increase muscle fiber area or to change muscle fiber type proportion.