What Is the Optimal Timing for Intradialytic Resistance Exercise? A Randomized Controlled Trial.

Abstract

This study aimed to examine the impact of intradialytic resistance exercise timing on blood pressure, physical performance, and muscle strength in patients in hemodialysis. A single-blind, randomized controlled clinical trial. Hospital-based hemodialysis unit. Forty-two patients in hemodialysis were randomly assigned to early or late exercise groups. Both groups performed the same resistance exercise protocol during either the first or last two hours of dialysis for eight weeks. The primary outcomes were post-dialysis systolic blood pressure and the number of intradialytic hypotensive episodes. Secondary outcomes included physical performance and lower extremity muscle strength. Post-dialysis systolic blood pressure declined less in the late exercise group than in the early exercise group (interaction effect: -5.4 mmHg; 95% CI, -10.72 to -0.25; p < 0.05). No significant difference in the number of intradialytic hypotensive episodes was observed between the groups (p > 0.05). Both groups showed significant improvements in blood pressure, heart rate, and physical performance (p < 0.05). Significant improvement was observed only in the left quadriceps femoris muscle in both groups (p < 0.05). Resistance exercise performed in the final two hours of dialysis is as safe and effective as that performed earlier. The smaller reduction in post-dialysis systolic blood pressure in the late exercise group may suggest a time-related clinical benefit.