AUTHOR=Francois Monique E. , Durrer Cody , Pistawka Kevin J. , Halperin Frank A. , Chang Courtney , Little Jonathan P. 

TITLE=Combined Interval Training and Post-exercise Nutrition in Type 2 Diabetes: A Randomized Control Trial

JOURNAL=Frontiers in Physiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2017.00528

DOI=10.3389/fphys.2017.00528

ISSN=1664-042X

ABSTRACT=<p><bold>Background:</bold> High-intensity interval training (HIIT) can improve several aspects of cardiometabolic health. Previous studies have suggested that adaptations to exercise training can be augmented with post-exercise milk or protein consumption, but whether this nutritional strategy can impact the cardiometabolic adaptations to HIIT in type 2 diabetes is unknown.</p><p><bold>Objective:</bold> To determine if the addition of a post-exercise milk or protein beverage to a high-intensity interval training (HIIT) intervention improves cardiometabolic health in individuals with type 2 diabetes.</p><p><bold>Design:</bold> In a proof-of-concept, double-blind clinical trial 53 adults with uncomplicated type 2 diabetes were randomized to one of three nutritional beverages (500 mL skim-milk, macronutrient control, or flavored water placebo) consumed after exercise (3 days/week) during a 12 week low-volume HIIT intervention. HIIT involved 10 X 1-min high-intensity intervals separated by 1-min low-intensity recovery periods. Two sessions per week were cardio-based (at ~90% of heart rate max) and one session involved resistance-based exercises (at RPE of 5–6; CR-10 scale) in the same interval pattern. Continuous glucose monitoring (CGM), glycosylated hemoglobin (HbA<sub>1c</sub>), body composition (dual-energy X-ray absorptiometry), cardiorespiratory fitness (<inline-formula><mml:math id="M1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mrow><mml:mtext>V</mml:mtext></mml:mrow><mml:mo>˙</mml:mo></mml:mover><mml:msub><mml:mrow><mml:mstyle class="text"><mml:mtext class="textrm" mathvariant="normal">O</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mstyle class="text"><mml:mtext>peak</mml:mtext></mml:mstyle></mml:mrow></mml:msub></mml:math></inline-formula>), blood pressure, and endothelial function (%FMD) were measured before and after the intervention.</p><p><bold>Results:</bold> There were significant main effects of time (all <italic>p</italic> &lt; 0.05) but no difference between groups (Interaction: all <italic>p</italic> &gt; 0.71) for CGM 24-h mean glucose (−0.5 ± 1.1 mmol/L), HbA<sub>1c</sub> (−0.2 ± 0.4%), percent body fat (−0.8 ± 1.6%), and lean mass (+1.1 ± 2.8 kg). Similarly, <inline-formula><mml:math id="M2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mrow><mml:mtext>V</mml:mtext></mml:mrow><mml:mo>˙</mml:mo></mml:mover><mml:msub><mml:mrow><mml:mstyle class="text"><mml:mtext class="textrm" mathvariant="normal">O</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mstyle class="text"><mml:mtext>peak</mml:mtext></mml:mstyle></mml:mrow></mml:msub></mml:math></inline-formula> (+2.5 ± 1.6 mL/kg/min) and %FMD (+1.4 ± 1.9%) were increased, and mean arterial blood pressure reduced (−6 ± 7 mmHg), after 12 weeks of HIIT (all <italic>p</italic> &lt; 0.01) with no difference between beverage groups (Interaction: all <italic>p</italic> &gt; 0.11).</p><p><bold>Conclusion:</bold> High-intensity interval training is a potent stimulus for improving several important metabolic and cardiovascular risk factors in type 2 diabetes. The benefits of HIIT are not augmented by the addition of post-exercise protein.</p>