The VIGORous Physical Activity for Glycaemic Control in Type 1 Diabetes (VIGOR) Trial (VIGOR)

Background/Justification: Regular physical activity (PA) has substantial health benefits in persons with type 1 diabetes (T1D), including reduced risk of complications and cardiovascular mortality. Despite these benefits, individuals with T1D remain significantly less active than their peers without diabetes. Two major factors likely explain the low rates of PA in young people with T1D: (1) fear of post-exercise hypoglycaemia, particularly nocturnal hypoglycaemia, and (2) a lack of empirical evidence for the efficacy of PA for achieving optimal glycaemic control. A number of acute exercise trials recently demonstrated that the inclusion of vigorous intensity PA in conventional moderate intensity (i.e. walking) PA sessions may overcome these limitations. No studies have tested the efficacy of high intensity PA for reducing the risk of exercise-related hypoglycaemia or glycaemic variability in a randomized controlled trial (RCT).

Study Hypotheses: In persons 15-35 years of age living with T1D, this study will test the hypotheses that (1) the addition of intermittent vigorous intensity PA to a moderate intensity intervention will reduce the time spent in hypoglycaemia in the 12 hour period following exercise and (2) the addition of intermittent vigorous intensity PA to a moderate intensity PA intervention will elicit significant improvements in glycemic excursions, as measured by the Mean Amplitude of Glycaemic Excursions (MAGE), in the 12-hour period following exercise.We are also exploring the hypothesis that reducing the risk of hypoglycemia will lead to a sustained increase in physical activity one year after randomization.