Adding Resistance Training To Endurance Training Improves Glucose Metabolism In Individuals With Metabolic Syndrome

Abstract

Elevated fasting blood glucose is one of the five components of metabolic syndrome (MetS) which is a cluster of anthropometric, metabolic and cardiovascular derangements. Insulin resistance (IR) has been identified as an important risk factor to develop diabetes (i.e, T2D) and MetS. Both, aerobic (AT) and resistance training (RT) prevent the development of T2D although it is unclear which is most effective. It has been suggested that mechanisms to improve IR are different between AT and RT. Thus, we hypothesized that the combination of both modes of training could provide additive effects to treat IR. PURPOSE: To determine whether the addition of resistance training (RT) to high-intensity interval training (HIIT) was able to improve glucose metabolism in patients with metabolic syndrome (MetS). METHODS: One hundred MetS patients (age, 56±8 years; weight, 92±17 kg; and Mets factors, 3.8±0.8 components) were randomized to undergo one of the following 16-wk program: (a) 4 x 4-min high-intensity interval training at 90% of HRMAX plus 3 sets of 8-12 rep at 60-85% 1RM of 3 legs free-weight exercises (HIIT+RT group; n=35), (b) 5 x 4-min high-intensity interval training at 90% of HRMAX (HIIT group; n=43) or (c) no exercise control group (CONT group; n=22). We measured the evolution of all five MetS components (i.e. Z-score), CRF (i.e. VO2max), legs strength and power (i.e. leg press 1RM and countermovement jump (CMJ)) and fasting glucose (FG) and insulin (FI) to calculate HOMA-IR before and after intervention. Pre-intervention FG was similar among groups (110±23; 115±21; 121±30, mg·dL-1 for HIIT, HIIT+RT and CON, respectively). RESULTS: After 16 weeks of training, HIIT+RT improved CMJ and 1RM leg press above HIIT and CON (P<0.010). After 16 weeks of training FG (4%; p=0.046) and HOMA-IR (18%; p=0.032), decreased only in HIIT+RT. However, both training groups improved similarly their VO2max (HIIT+RT, 7%, p=0.001; HIIT, 11%, p<0.001) and Z-score (HIIT+RT, 43%, P=0.022; HIIT, 63%, P=0.004). CONCLUSION: Our findings suggest that in initially sedentary individuals with MetS, RT combined with HIIT further improves the insulin-sensitizing effects of exercise reducing glucose concentrations.