Chronic kidney disease (CKD) consists of kidney damage, with consequent progressive and irreversible loss of kidney function. In the early stages of the disease, a reduction in circulating levels of the α-klotho protein is already observed, which is related to worsening renal function. Therapeutic strategies that increase serum levels of α-klotho may be of great value in the treatment of CKD. Electrical stimulation contributes to the reduction of reactive oxygen species, DNA damage and improves the effectiveness rate of dialysis, suggesting a systemic effect in patients with terminal CKD. The objective of this study is to evaluate the effects of whole body electrical stimulation on renal function and physical capacity in patients with CKD not dependent on dialysis.

Patients with stage III and IV chronic kidney disease will be randomized into two groups, one group will receive whole-body electrical stimulation and the other group will be a control group (it will only be evaluated and reevaluated at the same times as the intervention group). The intervention group will perform the protocol three times a week, for eight weeks. The following assessments will be conducted pre- and post-intervention: analysis of plasma content of soluble α-Klotho and creatinine to assess renal function; measurement of interleukins and tumor necrosis factor by ELISA to analyze the inflammatory profile; beta-endorphin measurement by ELISA to assess well-being; creatine kinase dosage to assess muscle damage; 10-repetition sit-to-stand test and quadriceps muscle dynamometry to assess lower limb muscle strength; handgrip test with a dynamometer to assess upper limb strength; six-minute walk test to assess functional capacity; application of the EuroQoL-5D questionnaire for quality of life and the Pittsburgh scale to assess sleep quality.

Inclusion Criteria:

• Patients diagnosed with CKD (≥ 3 months) in stages 3-4 (GFR between 59 and 15 ml/min/1.73m2);
• Age between 18 and 80 years old;
• Functional capacity ≥ 300 meters in the six-minute walk test.

Exclusion Criteria:

• Cognitive dysfunction that prevents assessments from being carried out or inability to understand and sign the informed consent form;
• Intolerance to electrical stimulator and/or changes in skin sensitivity;
• Skin injuries or burns where the electrodes are positioned;
• Patients with stroke sequelae;
• Recent acute myocardial infarction (two months);
• Uncontrolled hypertension (SBP>230 mmHg and DBP>120 mmHg);
• New York Heart Association grade IV heart failure or decompensated;
• Unstable angina or arrhythmia;
• Artificial cardiac pacemaker or implantable cardioverter defibrillator;
• Peripheral vascular changes in the lower limbs such as deep vein thrombosis;
• Disabling osteoarticular or musculoskeletal disease;
• Uncontrolled diabetes (glycemia > 300mg/dL);
• Patients with cancer and/or undergoing oncological treatment;
• Epilepsy;
• Hemophilia;
• Chronic obstructive pulmonary disease;
• Grade II obesity (BMI≥35).