The Comparison of High‑Intensity Interval Training and Moderate‑intensity Continuous Training on Inflammatory and Metabolic Variables in Type 2 Diabetes: Study Protocol for A Pilot Randomized Controlled Trial

The worldwide prevalence of type 2 diabetes mellitus (T2DM) is rapidly increasing, and research has shown that low‑grade inflammation leads to the development and progress of T2DM. Participating in physical activities, as part of the management program, is recommended to control inflammation and prevent the complications of T2DM. Although the most effective type and intensity of exercise training are not recognized yet, aerobic training has been reported to have beneficial effects. This manuscript describes the protocol of a study, in which we compared the effectiveness of 8 weeks of high‑intensity interval training (HIIT) and moderate‑intensity continuous training (MICT) on inflammatory, metabolic, and anthropometric variables in type 2 diabetes patients.

Methods/Design:

This study was designed as a pilot randomized controlled clinical trial with three parallel groups. Twenty‑seven adults with type 2 diabetes were randomly assigned 1:1:1 to HIIT, MICT, and control groups. Participants in the HIIT and MICT groups were invited to undertake three sessions of supervised exercise each week for eight consecutive weeks. HIIT sessions consisted of seven 1‑min intervals of running exercise on a treadmill at 90%–95% heart rate reserve (HRR) separated by 2 min of active recovery at 60%–70% HRR. MICT sessions involved 30 min of continuous running on the treadmill at 60%–70% HRR. Participants were assessed 24 h before the start and 24 and 72 h after the last training session. The control group, however, continued their everyday life during the project. The primary outcomes were the alterations of plasma calprotectin, myeloperoxidase (MPO), and interleukin‑6.

Evidence shows the link between inflammation and the development of type 2 diabetes complications. Therefore, finding ways to improve inflammatory state is of vital importance to these patients. This study is the first clinical trial comparing the impact of long‑term HIIT and MICT on calprotectin and MPO for people with type 2 diabetes.