Effects of an Aerobic Exercise Program on Cardiovascular Risk in Patients With Chronic Kidney Disease or Rheumatoid Arthritis

The goal of this clinical trial is to determine whether an aerobic exercise program can reduce cardiovascular risk in patients with systemic inflammation, such as those with rheumatoid arthritis and chronic kidney disease. The main questions this study aims to address are: * Does an individualized aerobic exercise program reduce cardiovascular risk, as assessed arterial stiffness and endothelial function ? * What are the effects of this exercise program on inflammation and immunosenescence? Researchers will compare an individualized aerobic exercise program with a therapeutic education program (consisting of educational phone calls only) and a control group with no intervention. Participants will: * Perform three physical activity sessions per week for six weeks (45-minute sessions at 60-80% of heart rate reserve); * Attend clinic visits at baseline, after the 6-week intervention, and at a 6-week follow-up after the intervention; * Undergo assessments including pulse wave velocity, hyperemic reactivity, and blood analyses.