Glycemic, inflammatory and oxidative stress responses to different high-intensity training protocols in type 1 diabetes: A randomized clinical trial.

AIMS: To investigate the effects of high-intensity interval training (HIIT) and/or strength training (ST) on inflammatory, oxidative stress (OS) and glycemic parameters in type 1 diabetes (T1DM) patients.

METHODS: After a 4-week control period, volunteers were randomly assigned to 10-week HIIT, ST or ST + HIIT protocol, performed 3×/week. Blood biochemistry, anthropometric, strength and cardiopulmonary fitness variables were assessed. Outcomes were analyzed via generalized estimating equations (GEE), with Bonferroni post hoc analysis.

RESULTS: ST, HIIT and ST + HIIT improved glycemic (HbA1c and fasting glucose) and antioxidant parameters (total antioxidant capacity, catalase and superoxide dismutase activities), but not plasma inflammatory (C-reactive protein, TNF-α and IL-10) or OS markers (thiobarbituric acid-reactive substances, 8-hydroxy-2-deoxyguanosine and oxLDL) levels. Noteworthy, interventions reduced soluble receptors for advanced glycation end products levels. However, intracellular heat shock protein 70 content increased only after HIIT. While daily insulin dosage decreased only in the ST + HIIT group, all training models induced anthropometric and functional benefits.

CONCLUSIONS: Similar benefits afforded by ST, HIIT or ST + HIIT in T1DM people are associated with enhanced antioxidant systems and glucose-related parameter, even in a few weeks. From a practical clinical perspective, the performance of ST + HIIT may be advised for additional benefits regarding insulin dosage reduction.