Priming Exercise in Type 1 Diabetes

Overview

Critical power is an important threshold in exercise physiology, and is an important determinant of the ability to tolerate high-intensity exercise. The ability to tolerate such exercise is drastically impaired in certain chronic conditions, such as type 1 diabetes. Whilst the most important physiological factors that determine critical power have yet to be determined, previous work from our laboratory suggests that it is related to the speed of oxygen uptake at the onset of exercise. This study will look to utilise "priming" exercise as an intervention to improve the speed of these oxygen uptake "kinetics", and thus critical power and exercise tolerance in individuals with type 1 diabetes. We hypothesize that oxygen uptake kinetics will be faster and critical power will be higher when exercise is performed with compared to without a prior bout of high-intensity priming exercise in a population of individuals with type 1 diabetes.

The ability to tolerate high-intensity exercise, or exercise tolerance, is a key factor that can influence clinical outcomes in a range of conditions. The "critical power" is an important physiological threshold that demarcates exercise intensities that can be sustained for prolonged periods (i.e. below critical power) from intensities that result in exhaustion in a relatively short period of time (i.e. 2-30 minutes, above critical power). Critical power is therefore a key determinant of exercise tolerance. The speed with which oxygen uptake rises at the onset of exercise (i.e. oxygen uptake "kinetics") has been shown by work from our laboratory to be a key determinant of critical power. One intervention that can acutely improve the oxygen uptake kinetics is the performance of a prior bout of high-intensity exercise, known as "priming exercise". Patients with type 1 diabetes have previously been shown to have impaired exercise tolerance compared to healthy controls. The performance of priming exercise therefore represents a potential intervention to acutely improve oxygen uptake kinetics, and therefore critical power and exercise tolerance, in type 1 diabetic individuals. The purpose of this study is therefore to assess the influence of priming exercise on oxygen uptake kinetics and critical power in a population of type 1 diabetic individuals.