PURPOSE: The current pilot and feasibility study was designed to examine the effect of 48 wk of moderate-intensity exercise training and dietary modification on kidney function and vascular parameters in chronic kidney disease (CKD) patients. METHODS: Twenty-one stage 2-4 CKD patients (age, 18-70 yr) were randomly assigned to either the training group (TG, n = 10) or the usual care group (n = 11) for 48 wk. The TG received 48 wk of personal training (3 d·wk for up to 55 min per session at 50%-60% V˙O2peak) and dietary counseling, whereas individuals in the usual care group received standard of care and were instructed not to start a structured exercise program while in the study. V˙O2peak, estimated glomerular filtration rate (eGFR), resting and ambulatory HR, plasma lipids (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides), and inflammatory markers (high-sensitivity C-reactive protein and interleukin 6) were assessed at baseline and weeks 24 and 48. An independent group's t-test was used to compare glomerular filtration rate slopes between groups, whereas all other data were analyzed with ANCOVA using the baseline value as the covariate. RESULTS: There were no statistically significant differences in any of the parameters at baseline. The 48-wk intervention led to a significant increase in V˙O2peak, reductions in both resting and ambulatory HR, and increases in LDL cholesterol and in TG, but it had no effect on the rate of change of eGFR over time. CONCLUSIONS: A 48-wk exercise training program, primarily focused on aerobic exercise, increases V˙O2peak and favorably alters autonomic function as evidenced by reductions in HR in stages 2-4 CKD patients. The exercise intervention had no effect on kidney function as assessed by eGFR.