Muscles need energy
About 90 percent of the body's creatine capacity is stored in the skeletal muscle. All living cells need energy – and muscle cells more than all other cells require large amounts of energy when in active use. Creatine helps to make this energy more easily available.
How does muscle gain the additional energy?
In the case of short, intense exercises – such as sprinting – the muscles need a great deal of energy in the shortest possible time. At the beginning of any such anaerobic exercise (independently of oxygen), the muscles must therefore resort to energy sources which are immediately available. These exist in the form of adenosine triphosphate (ATP) and creatine phosphate.
ATP and creatine phosphate act as a form of energy storage – a kind of battery – and help to bridge the time until the biodegradation of glucose (glycolysis), glycogen (glycogenolysis) and fat (lipolysis and fatty acid oxidation) release further energy to the body.
How is the energy released in the muscle?
ATP is energy needed for all biological processes. The ATP molecule has three so-called phosphate groups. If ATP breaks down a phosphate group, the resultant energy is released for the working of the muscles. What remains is adenosine diphosphate (ADP), which the body converts to ATP again by means of the energy present in food. However, this process takes a longer time, and produces sufficient ATP only for a few seconds. Therefore, the body has the additional possibility to regenerate ATP levels more quickly if the muscle performance required is longer and more intense: creatine.
How can creatine support muscle work?
In the resting muscle, creatine exists at about two-thirds of its capacity in the form of the energy-rich creatine phosphate, which contains an additional phosphate group. Even before the hard-working muscles run low in ATP, the enzyme creatine kinase (CK) transfers this phosphate group to the ADP and converts it back to ATP – but only as long as sufficient levels of phosphocreatine are present. This allows the muscles to work anaerobically until the supply of creatine phosphate becomes scarce. During the next resting phase, the created creatine is synthesized to creatine phosphate by the addition of a phosphate group. Once the supply of creatine phosphate has returned to its initial levels, it is then able to provide ATP again during the next round of intensive physical effort.
What causes creatine?
Creatine is an ideal nutritional supplement for athletes, as it promotes the transmission of energy within the cell structure in the form of creatine phosphate. The storage of creatine phosphate in muscular cells can be increased by an additional intake of creatine. This improves performance during periods of intense muscle strain, resulting in increased muscle build-up and greater strength. The larger creatine phosphate pool also leads to a faster regeneration of ATP, and thus supports recovery after intensive exercise at both training and competitive levels.