Moderate-intensity continuous training versus high-intensity interval training on insulin sensitivity andmaximal fat oxidation in adults with type 2 diabetes.

Resumo

INTRODUCTION: Type 2 diabetes (T2D) is a disease associated with distinctive features such as reduced insulin sensitivityand impaired ability to oxidize lipids at rest and during exercise (1). Recent studies have shown that physical exercise hasbeneficial effects on insulin sensitivity (2). Both high-intensity interval training (HIIT) and moderate-intensity continuoustraining (MICT) induce similar acute improvements in peripheral insulin sensitivity 24h after exercise and similar long-termmetabolic adaptations in skeletal muscle in adults (3). Thus, this study aims to compare the impact of HIIT and MICT oninsulin sensitivity and maximal fat oxidation (MFO) in adults with T2D, and whether these changes are related to eachother.METHODS: This is a preliminary analysis of EDUGUTION/APETEX/LIPIDOX randomized controlled studies with 46 subjectswith T2D (55.70 ± 6.97 years). Participants were allocated to MICT (n=20, 8 women), HIIT (n=15, 4 women) and controlgroup (CG) (n=11, 4 women). HIIT consisted of 10×1 intervals pedalling at 90% of peak power output, MICT consisted ofcontinuous pedalling at 10% above the first ventilatory threshold for 50 minutes, and the CG remained inactive. The program consisted of 12 weeks of training of three sessions per week on non-consecutive days. The measurements consisted of two days assessed before and after the intervention. On day 1, blood glucose was measured at fasting basal aswell as at 90 minutes in an oral glucose tolerance test. On the second day, MFO was evaluated through an incrementaltest on a cycle ergometer (15-W/3-min) with indirect calorimetry. A mixed factorial ANOVA with Bonferroni post hoc comparisons were applied. Pearsons correlation was performed with MFO and insulin sensitivity changes. Significance wasset at p<0.05.RESULTS: Basal and 90 min glucose levels significantly decreased in HIIT (p=0.046; p=0.019) and MICT (p=0.021; p=0.008). No significant results were found between groups or the time by group interactions. The MFO was significantly higher after 12 weeks of training (HIIT and MICT) compared to the CG, with a significant time by group interaction (p=0.010). In the MICT group, there is a significant correlation between MFO and insulin sensitivity (p=0.002).CONCLUSION: Both training programs improved insulin sensitivity and MFO in adults with T2D, being the HIIT a timeefficient exercise strategy in the management of T2D.