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Metabolic and cardiovascular benefits of high-intensity interval training in type 2 diabetes

University of British Columbia

High-intensity interval training (HIIT), comprised of alternating periods of brief high- and low-intensity exercise, has been shown to rapidly improve metabolic and cardiovascular health. As such, HIIT may provide a sufficient exercise stimulus to reduce cardiovascular risk in type 2 diabetes (T2D). Several studies have shown that HIIT is effective for improving glucose control and cardiorespiratory fitness. However, the acute and chronic effects of HIIT on the vasculature of individuals with T2D have yet to be established. The addition of post-exercise nutritional supplementation with high-quality protein from milk has previously been shown to augment favorable body composition changes with exercise interventions, which could promote further improvements in glycemic control and reduce cardiovascular risk factors in older adults with T2D. This thesis examines the impact of acute HIIT on vascular endothelial function, and the chronic metabolic and cardiovascular adaptations to HIIT with or without a post-exercise nutritional beverage, in individuals with T2D. In a randomized clinical trial, fifty-three individuals with T2D completed 12 weeks of low-volume HIIT (4-10 X 1 min intervals) with post-exercise nutritional support of non-fat milk, milk-protein concentrate or flavored water (placebo) beverage. Separately, thirty-five age-matched older adults (12 T2D, 12 untrained normoglycemic, and 11 trained normoglycemic) completed an acute session of cycling HIIT, leg resistance HIIT, or resting control. The principal findings of this thesis were: a) 12 weeks of HIIT improved glucose control, body composition, cardiorespiratory fitness and vascular function in individuals with T2D, b) no additive effects were observed with post-exercise milk or milk-protein supplementation, and c) acute resistance or cardio-based HIIT improves endothelial function in individuals with T2D. Noteworthy, the changes in blood pressure, arterial stiffness, femoral intima-media thickness and endothelial function were likely clinically beneficial based on magnitude based inferences that are associated with ~15-30% reductions in future cardiovascular events. Therefore, HIIT may be an effective means to reduce the burden of cardiovascular complications in T2D.

Text

2018-01-01

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/62164

Interdisciplinary Studies

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/