Effect of Two Intradialytic Exercise Programs on Heart Rate Variability in Hemodialysis Patients

Objective: To determine the effects of a non-immersive virtual reality (NIVR) program versus a conventional intradialytic exercise (CIE) program on heart rate variability (HRV) in individuals with chronic kidney disease (CKD) undergoing hemodialysis (HD).

Materials and Methods: A quasi-experimental study was conducted with 24 ambulatory patients from the HD unit of the Consorci Sanitari de Terrassa, Barcelona, Spain, between August and December 2024. Patients were assigned by convenience to the NIVR or CIE groups. A pre–post assessment was performed for variables related to the time, frequency, and nonlinear domains of HRV using the Polar H10 sensor.

Results: The CIE group demonstrated clinically significant improvements in variables such as the stress index (SI; d = 0.80) and SD2 (d = 0.63), reaching marginal statistical significance for both outcomes (P = 0.07 and P = 0.08, respectively). In contrast, the NIVR group showed small-to-moderate clinical significance in LF (d = 0.77), HF (d = 0.77), and SD2 (d = 0.43), with P > 0.05. A 40% reduction in cardiovascular risk was observed in participants initially classified as high risk in the CIE group (P = 0.02). NIVR was not superior to CIE in improving cardiac autonomic modulation.

Conclusion: CIE yielded more favorable outcomes in cardiac autonomic modulation compared with NIVR. However, given the study limitations, it is not possible to conclusively determine which program provides greater benefits. This research serves as a foundation for future studies designed to address the identified limitations and enable more robust comparisons.