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Creatine, an amino acid derivative also known as
a-methylguanidino acetic acid, was discovered in 1832 by a French scientist named Chevreul from a
meat extract. Its name is derived from the Greek word Kreas (flesh). Although
gains in strength and lean body mass have been attributed to it for quite some
time, it had only largely available in meat extracts until late in the twentieth
century. Creatine became one of the United State's most popular sports
supplements when Mark McGwire stated that he used it during the 1998 major
league baseball season, while participating in the race to the single season
home run record.
Typically, creatine users take approximately 20 g/d as a
'loading dose' for 5 days, and use 5 g/d as a 'maintenance dose.'
An average 70 kg adult stores approximately 120 g of creatine,
turning over 2-3 g per day. The vast majority of total body creatine is stored
in skeletal muscles, 60% of which is in the form of creatine phosphate. Although
it is produced naturally in the body, most is acquired from dietary sources.
Only 2% of the total body creatine store is synthesized by the liver, pancreas,
and kidneys.
Creatine Structure
Creatine is synthesized from three different amino acids:
arginine, glycine, and methionine. It is converted into creatinine before
elimination by the kidneys.
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