How does creatine work?
Around 90 percent of the body’s creatine stores are in skeletal muscle. All living cells need energy – and muscle cells in particular require large amounts of energy when they are in action. Creatine helps make energy available to muscle cells. How do muscles get the energy they need?
During short, intense exertion – sprinting, for example – muscle cells need a lot of energy in a very short time. At the beginning of such an anaerobic (independent of atmospheric oxygen) effort, the muscle must therefore resort to energy sources that are immediately available. These are in the form of adenosine triphosphate (ATP) and creatine phosphate.
Adenosine triphosphate and creatine phosphate are energy stores – in other words, a kind of battery – and bridge the time until the breakdown of glucose (glycolysis), glycogen (glycogenolysis) and fat (lipolysis and fatty acid oxidation) can release further energy.
How is energy released in muscles?
ATP is the energy currency for all biological processes. The molecule ATP has three so-called phosphate groups. When ATP splits off a phosphate group, energy is released for muscle work. What remains is adenosine diphosphate (ADP), which the body converts back to ATP with the help of the energy available in our food.
However, this process takes some time and there is only enough ATP available for a few seconds. Therefore, the body has an additional way to quickly regenerate ATP during prolonged muscle performance: Creatine or creatine monohydrate.
How can creatine (monohydrate) support muscle and muscle work?
In resting muscle, about two-thirds of creatine is in the form of the energy-rich creatine phosphate, which contains an additional phosphate group. Even before hard-working muscles run out of ATP, the enzyme creatine kinase (CK) transfers this phosphate group to ADP, converting it back to ATP – but only as long as there is enough creatine phosphate.
This allows the muscles to continue working anaerobically until the supply of creatine phosphate runs low. During the next resting phase, the resulting creatine is rebuilt into creatine phosphate by adding a phosphate group. Once the creatine phosphate supply returns to its initial level, it is able to provide ATP during the next intense effort.
Taking creatine monohydrate as a dietary supplement or supplementation can therefore support muscle building in that it provides a phosphate group as creatine phosphate to supply energy to the muscles.