All legit questions. In fact generally speaking people don't know much about it, although creatine is one of the most popular bodybuilding supplements.
So let me start answering your question.
Creatine is a natural molecule found in muscle in the form of creatine phosphate.
Creatine is a substance formed from the amino acids arginine, methionine and glycine. It is produced mainly in the liver (but also by the pancreas and kidneys) and localized for 95% in muscle, while a small part is in the heart and brain.
From the liver it is transported in the blood and then it gets in the muscles. There it is transformed into creatine phosphate (or phosphocreatine) and stored.
What is Creatine and What Does it Do?
Being crucial for the ADP-ATP energy cycle, creatine is a substance that plays a fundamental role in muscle contraction. The need to use large amounts of ATP per time unit justifies the use of creatine supplementation, that will be converted into creatine phosphate (which is not assimilable orally) in the body.
The creatine phosphate "gives" the phosphate group to ADP (adenosine diphosphate) turning it into ATP.
By providing energy, ATP loses a group of phosphate becoming ADP again that can be loaded again for effect of the creatine phosphate.
Why Should I Take Creatine?
I guess this is the real question. So far I answered what is creatine and simply explained the theory behind, but from the bodybuilder point of view that is just a bunch of words that mean nothing, right?
What we are interested in are the results. We want to know what creatine can do for us, and what it can improve.
There are a few valid reasons why making use of creatine supplementation can be beneficial. Some people use creatine to lose weight as well.
Usually people take creatine supplements to:
- Promptly restore energy reserves used during physical activity
- Facilitate the transfer and distribution of energy
- Moderately stimulate protein synthesis
- Hydrate and increase muscles size (due to protein synthesis)
Which Foods Contain Creatine?
Creatine is still present in small amounts in meat, but creatine supplementation (in the dose prescribed by law) is recommended in all sports disciplines that need a high ATP turnover.
Taking creatine monohydrate involves:
- Increase in the total creatine content in the muscle
- Increase of the amount of usable ATP
- Increase in anaerobic power alactacid
- Increase in the buffer capacity with improved ability to neutralize lactic acid (lattacide performance and aerobic high intensity)
- Increased re-synthesis of creatine phosphate in muscle