Outcomes of long-term exercise training in dialysis patients: comparison of two training programs

Exercise training has been shown to improve the low functional capacity and quality of life in dialysis (HD) patients. However, there are no data about the outcome of long-term exercise training and, also, the adherence of HD patients in such long-term renal rehabilitation programs. Therefore, the aim of this study was to evaluate the effects of 2 modes of long-term physical training on HD patients' physical fitness, perception of health and overall life situation.

Forty-eight HD patients, free of any other systemic disease, who followed 2 modes of exercise training for 4 years, were studied. Half of them (group A) were randomly assigned to participate in a supervised outpatient exercise training program (3/weekly) on the non-dialysis days, while the other half (group B) followed a training program with stationary bicycles during their HD sessions (3/weekly). The measured domains of physical fitness and well-being every year were: aerobic capacity, as estimated from a modified Bruce treadmill exercise test and spiroergometric study, the patients' perception of health, the overall life situation and the employment status.

During the 4-year study, there were 8 drop-outs in group A and 5 in B. No adverse effects of the exercise programs were reported. The 1 year of exercise training resulted in 38% in group A (16 patients, who remained in the study) and 31% in group B (18 patients) improvement of exercise time, and a 47% increase in group A of peak oxygen consumption (VO2peak) and a 36% in group B in comparison to baseline value. After 3 additional years of training, significant improvements were also noted in exercise time (by 53% in group A and by 43% in B) and VO2peak (by 70% in group A and by 50% in group B), as well as in other gas exchange variables in comparison to baseline values. However, the improvements in group A were more pronounced than in B. Interestingly, the gains in exercise capacity were more enhanced in the first year of training in both groups. After 4-year training, significantly more patients in both groups perceived their health and overall life situation as well, compared to baseline. In addition, perception of improved health was higher in group A. The increase in the proportion of patients working was also higher in group A than B after the 4-year training.

HD patients can adhere to long-term physical training programs on the non-dialysis days, as well as during hemodialysis with considerable improvements in physical fitness and health. Although training out of HD seems to result in better outcomes, the drop out rate was higher.