The Effect of a Mixed-type Intradialytic Exercise Training Program on Body Composition, Functional Capacity, and Muscle Oxygenation of the Upper and Lower Limbs in Hemodialysis Patients

Chronic kidney disease (CKD) is a progressive clinical condition that affects a growing number of people worldwide. While advances in haemodialysis techniques have led to notable improvements in survival rates and the quality of life (QoL) of patients with CKD (PwCKD), significant complications persist, primarily associated with chronic uremia. These include skeletal muscle atrophy, reduced muscular strength and diminished functional capacity. Recent studies support the role of systematic exercise as a non-pharmacological strategy to reduce issues and improve musculoskeletal function among haemodialysis patients. Specifically, intradialytic exercise gained ground due to its efficiency in time utilization and elimination of transport burden. Nevertheless, most of the intradialytic exercise programs implement aerobic exercise and there is a lack of studies investigating combined strength and aerobic exercise modalities, which may offer more comprehensive physiological benefits. The aim of the randomized controlled trial (RCT) is to examine whether a 6-month combined aerobic and resistance exercise program, implemented during haemodialysis sessions, could affect body composition, muscle oxygenation of the lower and upper extremities, and functional capacity of patients that underwent haemodialysis. Forty patients will be randomly allocated into two groups: Group A (Exercise Group) will undergo 3 sessions per week of an intradialytic exercise program for 6 months and Group B (Control Group) will receive the usual care without participating in organized exercise programs. Prior to the group random allocation, part of our assessments at baseline and after 6 (Evaluation A') will include demographics and clinical history, body composition analysis via bioelectrical impedance analysis, muscle oxygenation monitoring of the vastus lateralis and biceps brachii muscles at rest and during exercise using near-infrated spectroscopy (NIRS) technology. Functional capacity will be