Effects of Exercise on Sarcopenia and Frailty in Haemodialysis Patients: A Systematic Review

Background and Objectives: Chronic kidney disease is characterized by the progressive loss of functioning nephrons due to structural and functional alterations in the kidneys. It is clinically defined through the presence of a glomerular filtration rate below 60 mL/min/1.73 m² or persistent kidney damage lasting at least three months. Patients undergoing haemodialysis frequently present with sarcopenia and frailty. The aim of this study was to evaluate the effects of intradialytic exercise on sarcopenia and frailty in individuals with chronic kidney disease. Materials and Methods: A systematic review was conducted in accordance with PRISMA guidelines. Electronic searches were executed in PubMed, PEDro, Scopus, and Dialnet. Eligible studies included adults (≥18 years) on haemodialysis who engaged in exercise interventions compared with passive control groups. Exclusion criteria included any conditions conflicting with the inclusion criteria, systematic reviews, study protocols, and articles not meeting the PICO framework or contradictory to the inclusion criteria. Outcomes of interest were sarcopenia and frailty, assessed through measures of physical function and muscle strength. Methodological quality was appraised using the PEDro scale, and risk of bias was evaluated with the Cochrane Risk of Bias tool. Results: Fifteen studies met the inclusion criteria. Most interventions consisted of aerobic training, resistance training, or combined exercise programs. Across studies, exercise interventions consistently improved physical function and muscle strength, although no significant effects on body composition were observed. Conclusions: This systematic review provides evidence that intradialytic exercise may produce clinically relevant improvements in sarcopenia by enhancing muscle strength and functional performance, as measured by tests such as the sitting-to-standing test. These results suggest that intradialytic exercise could be beneficial for patients with chronic kidney disease.