Chronic kidney disease and renal replacement treatments (hemodialysis, peritoneal dialysis, kidney transplant) produce various alterations at the level of muscle, bones, fat content and the heart; can alter physical capabilities such as muscle strength, resistance to climb a step repeatedly intensely, and the ability to move the joints freely, in addition to producing an increase or decrease in weight and alterations in its distribution (for example, decreasing muscle and increase fat). The above, added to the particular factors of hemodialysis such as the reduction in daily time to exercise due to the sessions, or the fatigue after it, can together generate greater repercussions on functional capacity and thus increase the risk of suffering from cardiovascular problems. and accelerate the evolution of the disease.

Therefore, this study aims to determine the effect of a 12-week supervised physical exercise program during hemodialysis on strength and ability to move, the amount of fat and muscle in the body, as well as bone wear. ; and compare these results with a group of patients who do not perform supervised exercise. In addition, it will be determined how exercise can act in the long term, preventing the risk of hospitalization and death due to cardiovascular causes. The above is useful in order to establish recommendations and protocols that help us increase the quality of life and survival of the person.

Background: In Mexico, Chronic Kidney Disease (CKD) has a high prevalence and is considered one of the leading causes of death. Hemodialysis (HD) is the primary renal replacement therapy; however, it is associated with significant declines in functional capacity, body composition alterations, morbidity, hospitalization, and mortality with rates that can be 30% higher than those in the general population not on HD. It is estimated that 50% of patients die within the first three years of starting HD, primarily due to cardiovascular complications. Intradialytic exercise has been linked to improvements in functional capacity and metabolic and cardiovascular parameters in HD patients. Despite these benefits, there are few studies examining the relationship between intradialytic physical exercise and increased survival in CKD patients.Objective: To analyze the effects of a 12-week intradialytic exercise program on functional capacity, body composition, and survival in patients undergoing hemodialysis. Hypothesis: A 12-week intradialytic exercise program will improve functional capacity, body composition, and survival rates in hemodialysis patients. Materials and Methods: This clinical trial will utilize a randomized design with two groups of HD patients. The intervention group will participate in an aerobic and muscular resistance exercise program during the second hour of dialysis, three times a week for 12 weeks. The control group will not participate in intradialytic exercise but will receive guidance on standard treatment, including recommendations for aerobic and resistance exercises at home three times a week. All participants (both the intervention and control groups) will be assessed for body composition using bioelectrical impedance analysis, functional capacity through the 6-minute walk test, the 30-second sit-to-stand test, and muscle strength measured by hand dynamometry. The primary outcome variable will be the survival rate at eight months of follow-up after the exercise intervention, and during this time, the International Physical Activity Questionnaire (IPAQ-short version) will be administered every two months.

Inclusion criteria:

1. Male and female patients aged between 18-50 years.
2. Patients who receive regular hemodialysis sessions 3 times a week, reported through the clinical record.
3. Patients with a clinical history of being treated with HD for at least 1 previous year (reported by clinical record).
4. Patients without a history of myocardial infarction in the last 3 months (reported by clinical record).
5. Patients who are not in a kidney transplant protocol to be performed during the next 12 months.
6. Patients who have permission from their nephrology specialist to participate.
7. Patients who agree to participate in the study, and who voluntarily sign the informed consent (IC) form.
8. Patients without a history of coronary artery disease in the last 4 months (reported by clinical record).
9. Patients without myocardial instability (angina, decompensated congestive heart failure, severe arteriovenous stenosis, uncontrolled arrhythmias), reported by clinical record.
10. Patients without active infectious process (reported by clinical record).
11. Patients without extreme changes in blood glucose levels (hyperglycemia or hypoglycemia), reported by clinical record.
12. Patients without neurological, respiratory or skeletal muscle diseases or disorders that are aggravated by exercise (reported by clinical record).
13. Patients without inability to sit, stand or walk without assistance (walking device such as cane or walker is allowed) self-reported.
14. Patients without severe anemia (Hb < 8.0 g/dL), reported by clinical record.
15. Female patients should not be under sex hormone treatment or hormone replacement therapy for menopause (self-reported).
16. Patients without lupus erythematosus as the etiology of CKD, reported by clinical record.
17. Physically inactive (Do not perform physical exercise of more than 150 minutes per week on a regular basis according to data from the World Health Organization).
18. Patients who do not have amputations of any of the extremities.

Exclusion criteria:

1. If the patient presents any disease, or neurological, respiratory or skeletal muscle disorder during the development of the physical capacity tests, or during the execution of the protocol, which is aggravated by the practice of physical exercise.
2. When the patient voluntarily decides to leave the study.
3. When the patient begins additional strength or aerobic training.
4. Patients who receive a kidney transplant during the development of the exercise protocol or follow-up during the 8-month follow-up period.
5. Patients who decide to belong to the group that will perform intradialytic exercise.
6. When for any reason the exercise is suspended for more than three continuous times.

Start: January 20, 2025. End May 30, 2026