Investigating the effect of stationary cycling exercise during dialysis on dialysis adequacy and laboratory parameters of hemodialysis patients

‏Objective: To evaluate the effect of stationary cycling during dialysis on dialysis adequacy and laboratory and hemodynamic parameters of hemodialysis patients in Isfahan. ‏Specific Objectives: To compare baseline, laboratory, Kt/V, and hemodynamic parameters before and after the study between intervention and control groups.

Parallel-group clinical trial with 70 hemodialysis patients (35 per group) randomized via Simple Randomize. Data analyst blinded.

Eligible patients in Isfahan are randomly assigned to intervention or control.

Age ≥ 18 years Written informed consent Chronic kidney failure on maintenance hemodialysis ≥ 3 months At least 3 hemodialysis sessions per week No hospitalization in the past month No diagnosed psychiatric or cognitive disorders Physically able to perform exercise on a stationary bicycle during dialysis Exclusion Criteria (Not eligible to participate): Age < 18 years Lack of written informed consent Hemodialysis < 3 months or not on maintenance hemodialysis Fewer than 3 hemodialysis sessions per week Hospitalization within the past month Diagnosed psychiatric or cognitive disorder Not physically fit to exercise on a stationary bicycle during dialysis

Participants in the intervention group will exercise on a stationary bike during hemodialysis sessions. The control group will receive standard hemodialysis care without exercise

Dialysis adequacy; laboratory and hemodynamic parameters

In this study, participants were assigned to the intervention or control group using simple randomization through the Simple Randomize software. Randomization was performed at the individual level, and allocation concealment was ensured by the software so that neither researchers nor participants could predict group assignment prior to enrollment.

Due to the nature of the intervention (using a cycle ergometer during hemodialysis), participants cannot be blinded to their group assignment, as the physical experience of the intervention is observable and tangible. However, to minimize bias in data collection and analysis, the following measures were implemented: Clinical caregivers and healthcare personnel responsible for patient care were kept unaware of group allocation, and uniform care protocols were applied to all patients so that the intervention effect could not be distinguished from routine care. Data collection was conducted by a team member who knew the group assignments; however, data were coded and provided to the data analyst in a de-identified manner. The data analyst remained blinded to the group assignment, and all analyses were performed based on anonymized codes. The principal investigator and study conductors had no access to individual group assignments, ensuring that decisions and analyses were independent of group allocation. The Data Safety and Monitoring Committee (DSMC), if applicable, could access anonymized data but no information regarding specific group assignments was disclosed to the analyst or clinical staff. Thus, although participants could not be blinded due to the nature of the intervention, clinical caregivers, data collectors, and the analyst were effectively blinded to minimize potential bias and preserve the validity of the study results.