Beta-Alanine is a non-essential amino acid that is used by muscle cells to synthesize Carnosine. Carnosine is a dipeptide (Beta-Alanine plus Histidine) that functions as a buffer for the hydrogen ions (acid) produced during strenuous exercise, thus helping to maintain optimum muscular pH. Clinical studies suggest that Beta-Alanine supplementation can increase muscle Carnosine content and delay muscle fatigue.

Articles on Beta-Alanine:

http://en.wikipedia.org/wiki/Beta-Alanine