Beta-alanine is a non-essential amino acid that can help increase the natural level of carnosine in muscles. Carnosine assists in buffering the overload of hydrogen ions produced from intense resistance training that can make muscles more acidic. Researchers at the college of New Jersey studied the effect of 30 days of beta-alanine supplementation (4.8g per day) on resistance training in eight experienced, resistance-trained men. They performed 6 sets of 12 repetitions of the squat exercise at 70% of their one-rep maximum with 1½ minutes of rest in between sets. At the end of four weeks, those taking beta-alanine showed a 22% improvement compared to placebo, indicating that beta-alanine can significantly improve muscular endurance in experienced resistance-trained athletes.
Reference: International Journal of Sports Medicine; June 11, 2008, electronic pre-publication.