The base of the muscle is composed of filaments. During the year, they slide against each other. Therefore, the muscle shortens and hardens. The filaments act as hooks, allowing the contraction and muscular relaxation, avoiding a rupture. They are the ones that give elasticity to the muscle.
So that muscle fibers can contract, they need a helping hand, a “spark”, like a car. The candle of the muscle is adenosine triphosphate (ATP). This amino acid is used to store and transport energy. But it runs out very quickly, in one or two seconds.
If the muscular effort continues, the body must find a new source of energy. Fortunately, the muscles contain other reserves to weather the storm: the glycogen example. This is the form in which we store glucose. It helps us to fight against the famous crack. Consider the image of the sport that carries with it some lumps of sugar. At each meal, so it is advisable to eat a carbohydrate food. Before a sport of endurance, focus on carbohydrates, bread, pasta or rice. Consumed the previous day, they will help you perform better. Sport and sugar are not necessarily incompatible.