Glucose is known by most as the 'body's source of energy' and this play on words is even used by the energy drink Luco-zade. When you eat food the cells in the body take glucose from the bloodstream and turn it into energy. Most organs in the body rely on glucose as fuel to function properly. To keep functioning properly, the body aims to keep a constant stream of glucose flowing through its cells to stop the cells starving in between meals and whilst you're asleep.
If the body takes in a surplus of the glucose needed to function properly, it stores the excess in the liver and around muscles, thereby creating glycogen (long chain stores of glucose). If, in another instance, the body runs low on glucose, it looks to the glycogen store and mobilises it to provide the needed glucose. Glycogen is stored in a manner that is easily accessible and metabolised for instant energy. These stores should not be confused with fat, which is harder to break down.
A beneficial element of glycogen lies in its ability to be broken down and turned into energy, even in the absence of oxygen. This is especially useful during arduous physical activities or exercises. Glucose and Glycogen are carbohydrates, with glucose known in medical terms as monosaccharide and sugar and glycogen being a more complex chain of glucose molecules.
One molecule of glycogen can contain anywhere between 2,000 to 500,000 glucose units. Up to 1% of the weight in the muscles and around 5% of the weight in the liver is made up of glycogen. Glycogen is not water soluble like glucose and needs to be broken down to be of any use to the body. Extended durations of exercise can use up a person's store of glycogen and this can be problematic for people that have diabetes, as they can develop hypoglycemia (low blood sugar levels) as the body needs to replenish its store of energy using glycogen stores in the liver. On the other hand, using up the glycogen stores is useful for those looking to lose weight; if your body runs out of glycogen stores, it is forced to resort to the fat deposits left in the body, forcing the body to break down the fat stored, resulting in weight loss.