Effects of Two Low-Frequency Intradialytic Cycling Training Programs on Functional Capacity in Subjects Undergoing...

Functional capacity deteriorates over time in patients on hemodialysis, which is associated with increased mortality risk. This study aimed to assess the effects of two low-frequency (i.e., twice weekly) intradialytic cycling exercise training programs-low- to moderate-intensity continuous training (L-MICT) versus moderate- to high-intensity interval training (M-HIIT) - on functional capacity in patients undergoing hemodialysis.

Sixty-seven out of sixty-nine patients undergoing hemodialysis of both sexes (44 men and 23 women), aged 35-55 years, completed this study. Patients were randomly assigned to three groups: L-MICT group (n = 23), M-HIIT group (n = 21), and nonexercise control group (n = 23). Patients in the L-MICT group performed intradialytic cycling exercise continuously at a low-to moderate-intensity for 20-30 min. Patients in the M-HIIT group performed 3 × 3-min moderate- to high-intensity cycling exercise, separated by 4-min low-intensity active breaks. The intradialytic cycling programs were scheduled twice a week for 8 weeks. The outcome measure was the functional capacity assessed by the 6-min walk test (6MWT).

The 6-min walk distance (6MWD) increased significantly in the L-MICT group [p = 0.004, the change score (Δ) = 18.2 meters (m)], in the M-HIIT group (p = 0.001, Δ = 17.6 m), and in the control group (p = 0.014, Δ = 11.4 m) compared to baseline. However, no significant differences were found between groups.

Low-frequency intradialytic cycling training programs, either L-MICT or M-HIIT, twice a week for 8 weeks, could similarly induce statistically significant improvements in the 6MWD in people receiving hemodialysis. Nevertheless, the 6MWD changes did not exceed the minimally detectable change previously reported in this population.