Glycogen is a polysaccharide composed of many glucose molecules. It plays an important role in feeding the muscles during exercise and is also a great source of energy. Indeed, the body’s glycogen content decreases during training, which can lead to reduced strength and general weakness throughout the body. So, what is glycogen, where does it accumulate and what exactly are its functions? And finally, what should you eat and when should you eat it to ensure your glycogen stores are sufficient for long, intense workouts?
What is glycogen exactly?
Glycogen is the main polysaccharide that forms the reserve material of animal cells. It is structurally similar to amylopectin, which is the main component of the starch. Glycogen is largely stored in the liver (5-10% of its total weight), from which it is drawn as an energy source for the brain and muscles. The release of glycogen from the liver is controlled by pancreatic and adrenal hormones. Glycogen is also found in skeletal muscle, where it is about 7 times less present than in the liver. The so-called muscle glycogen is only used by the body to fuel the muscles, and its content in the muscular system can be increased up to twofold by training and proper nutrition. Visit a specialist website to find out what type 2 diabetes really is.
The main characteristics of glycogen
Glycogen is formed in the liver by a process called glycogenesis. It involves the binding of glucose in the blood, resulting in the formation of glycogen. Glycogenesis is most active at rest and is controlled by the pancreas, which injects an appropriate amount of insulin into the bloodstream after a sudden increase in glucose levels (for instance, after a meal).
The main functions of glycogen
Glycogen has the important function of storing animal energy reserves. It is progressively used by the muscles and brain during training and intensive mental work. In scientific literature, glycogen is referred to as the body’s carbohydrate reserve. Two types of glycogen can be distinguished, each responsible for different functions:
- Liver glycogen: stored in the liver, where its quantity is generally between 60 and 150 grams. It is a reserve source of energy for red blood cells and nerve cells (neurons). A small amount of liver glycogen is also used to fuel the muscles during extremely intensive training.
- Muscle Glycogen: This type of glycogen is much more important for people who do intense sports. As the name suggests, it is stored exclusively in the muscles. It is therefore only used by the muscle cells. The glycogen content of the muscles is successively reduced (breakdown of glycogen into glucose, which is oxidised) during training, and its low level can lead to a decrease in the intensity of the effort, as well as coordination problems. It is therefore useful to remedy this deficiency after training.