To maintain stable blood sugar levels during exercise, the body implements a number of complex mechanisms, notably in the nervous and endocrine systems. Glucose is an essential source of energy, particularly during prolonged exercise, and the body must constantly adjust its production and use to meet the needs of the muscles without upsetting blood sugar balance.
During exercise, muscles use more glucose, leading to an increase in its absorption.
Two main elements facilitate this phenomenon: insulin release and muscle contractions. Together, they activate a protein, GLUT4, which transports glucose into muscle cells.
In addition, the body increases blood supply to the muscles to ensure better glucose availability.
Blood glucose levels are kept stable in several ways:
- Hepatic degradation of glycogen: the liver releases glucose stored in glycogen to fuel the muscles.
- Gluconeogenesis: when exercise is prolonged and glycogen stores are depleted, the liver manufactures glucose from other compounds (such as amino acids or lactate).
- Using fat: the body can also draw on fat as an energy source, reducing dependence on glucose.
Blood glucose control relies on two types of mechanism:
- Feedforward: at the start of exercise or during intense workouts, the body anticipates glucose requirements and increases its production, sometimes in excess, which may even raise blood glucose levels slightly.
- Feedback: if blood glucose levels fall during prolonged exercise, corrective mechanisms are activated to stabilize them.
In short, the body adapts dynamically to balance blood glucose levels during exercise,
mobilizing different energy sources and regulatory systems in turn.
Learn more about Pep2Dia to maintain a healthy glycemia!
Sources:
Regulation of blood glucose homeostasis during prolonged exercise.
Suh SH, Paik IY, Jacobs K.
Mol Cells. 2007 Jun 30;23(3):272-9.
PMID: 17646701