There is evidence for significant beneficial effects of regular exercise on physical fitness, walking capacity, cardiovascular dimensions (e.g. blood pressure and heart rate), health-related quality of life and some nutritional parameters in adults with CKD. Other outcomes had insufficient evidence due to the lack of data from RCTs. The design of the exercise intervention causes difference in effect size and should be considered when prescribing exercise with the aim of affecting a certain outcome. Future RCTs should focus more on the effects of resistance training interventions or mixed cardiovascular- and resistance training as these exercise types have not been studied as much as cardiovascular exercise.
Effects of recombinant human erythropoietin and exercise training on exercise capacity in hemodialysis patients.
The effects of recombinant human erythropoietin (rHuEPO) and exercise training on exercise capacity were evaluated in 20 hemodialysis patients. After improvement of anemia by rHuEPO (Phase I), patients were divided into 2 groups. Group 1, 10 patients, was placed in a 3-month exercise training program. Group 2, 10 patients, served as a control group (Phase 2). A symptom-limited exercise tolerance test was performed at the start of Phase 1 and before and after Phase 2. Hemoglobin (Hb) values were kept constant throughout Phase 2. In Phase 1, maximum workloads (62.0 +/- 19.1 to 76.5 +/- 25.6 W, p < 0.001), maximum O2 uptake (VO2max) (18.7 +/- 3.5 to 2.2 +/- 5.9 ml/min/kg, p < 0.01), and VO2 at anaerobic threshold (AT) (VO2AT) (8.5 +/- 2.1 to 10.2 +/- 2.9 ml/min/kg, p < 0.01) were all improved by rHuEPO. However, in Phase 2, despite unchanged Hb values and maximum workloads, VO2max (20.7 +/- 4.6 to 17.6 +/- 2.6 ml/min/kg, p < 0.05) and VO2AT (10.6 +/- 1.4 to 9.5 +/- 1.8, ml/min/kg p < 0.05) were decreased in Group 2. However, in Group 1, maximum workloads (66.7 +/- 8.2 to 81.7 +/- 7.5 W, p < 0.01) were improved, and VO2max and VO2AT were not decreased significantly in the same period. Exercise training in rHuEPO-treated hemodialysis patients resulted in an improved aerobic exercise capacity, whereas those without exercise training did not have increased capacity. Throughout the study, O2 uptakes were lower than those of nonrenal anemic patients who had similar Hb values. Maximum lactate values also remained low. In conclusion, improvement in the exercise capacity in hemodialysis patients treated with rHuEPO was minimal. Some defects were suggested in the aerobic energy production system in skeletal muscle of dialysis patients. Anemia-improved patients should participate in incremental physical activity to maintain an improved exercise capacity.