Creatine

A nitrogen compound synthesised by the liver from arginine, glycine and methionine, naturally present in meat and fish. Stored in muscles as phosphocreatine, it is the energy substrate for the alactic anaerobic pathway (short, intense efforts). Dietary intake represents 50% of needs, the rest being synthesised endogenously. Vegetarians have naturally 20 to 30% lower muscle creatine stores. Studies also show an effect on working memory, particularly in vegetarian populations.