Capillary Glycerolemia Evolution During Physical Exercise

The metabolism of mobilized fatty acids as an energy reserve during physical exercise produces glycerol, which makes it a marker of the intensity of lipolysis.

This measurement of the intensity of lipolysis in humans can be carried out according to several methods. Since glycerol is a product of lipolysis, its rate of appearance (Ra) in the blood represents a physical quantity naturally associated with lipolysis activity. Unfortunately, its quantification requires the use of a tracer isotope (deuterated glycerol), which limits its applicability. The alternative is the determination of glycerolemia in the blood or in the interstitial fluid via a microdialysis probe placed in subcutaneous adipose tissue;

Recently, a measuring device has been proposed which makes it possible to measure glycerolemia from capillary blood, in the manner of measuring blood glucose in diabetic patients. This device has the advantage of being used repeatedly after a physical exercise. This flexibility also makes it possible to consider the personalization of the sports program by identifying the circumstances associated with an increase in lipolysis such as the type of meal preceding the exercise or its intensity.

Evidence suggests that moderate-intensity exercise (about 45% -65% VO2max) performed under fasting conditions maximizes lipid metabolism as a source of energy, compared with carbohydrate metabolism. But these data conceal a likely significant variability in individual outcomes, including levels of training, gender, age, and nutritional intake prior to exercise. Our hypothesis is that the current recommendation to the diabetic patient, or with a metabolic syndrome, to exercise moderate intensity fasting physical activity could be adapted individually to each patient in order to optimize the benefits of such a practice. In this sense, the easy access to a measurement of capillary glycerolemia could make it possible to identify in a personalized way the type of physical activity.

This research project aims to accurately describe the evolution of capillary glycerolemia in several configurations of physical exercise (variable intensity) by controlling the effect of the previous meal. It will also seek to identify situations associated with a greater increase in capillary glycerolemia to pave the way for personalization of the sports activity program.