The effects of combined high-intensity interval and resistance training on glycemic control and oxidative stress in T2DM

Background: As part of type 2 diabetes mellitus (T2DM) lifestyle management, exercise programs must be demonstrably effective and safe. Objectives: A randomized controlled trial (RCT) was used to evaluate the results of glycemic control and oxidative stress of a new T2DM management exercise program in a training facility setting. Methods: The study participants were randomly allocated into either an experimental (EXP) group who participated in the new training program or a control (CTR) group who participated in continuous cardiorespiratory exercise. Each participant’s glycemic control (glycated hemoglobin A, HbA1c), fitness level (maximum oxygen uptake, VO₂max), and oxidative stress (malondialdehyde, MDA and superoxide dismutase, SOD) were measured before and after the training program. The 12-week training program combined high-intensity interval training (HIIT) three times a week with resistance training (RT) twice a week while gradually increasing the intensity. The HIIT element was comprised of one minute of high-intensity exercise and four minutes of low-intensity exercise. The RT element was comprised of nine exercises for the core, upper extremities, and lower extremities. Results: The 42 T2DM patients who participated in this RCT were 35-64 years old. The HbA1c level of the EXP group decreased (∆ =-0.43 ± 1.01%), although not significantly. The VO₂max was higher in the EXP group (38.13 ± 5.93 mL/kg/min) than in the CTR group (32.09 ± 5.24 mL/kg/min, P = 0.004). The overall oxidative stress decreased in the EXP group (MDA level ∆ =-0.14 ± 0.39 nm/mL) when compared to the CTR group (MDA level ∆ = 0.18 ± 0.26 nm/mL, P = 0.011), and the SOD level significantly increased more in the EXP group [median ∆ = 0.47 U/mL (interquartile range = 0.08-0.74 U/mL)] when compared to the CTR group (∆ = 0.14 ± 0.35 U/mL, P = 0.036). The EXP group’s composite effects score was significantly higher (8.72 ± 1.27) than the CTR group’s score (7.20 ± 1.08, P = 0.001). Conclusions: The combined HIIT and RT exercise program was not significantly improving glycemic control, however it lowered oxidative stress.