Most bodybuilders are aware that beta-alanine has performance-enhancing effects in the gym. An early study reported that knee-extension force was significantly increased during five sets of 30 maximal contractions by beta-alanine supplementation, whereas, in the placebo group, only the first two bouts were improved. This shows that in trained athletes performing repeated exhaustive contractions, muscle fatigue can be reduced in the later (bouts 4 and 5) stages of exercise with beta-alanine. Beta-alanine enhances the concentrations of carnosine in the muscle. Elevated levels of muscle carnosine content leads to an improvement in muscle force during repeated bouts of intense dynamic contractions.
Now, new studies from the Journal of the International Society of Sports Nutrition show that beta-alanine could also improve isometric contractions. When subjects were administered 6.4 grams of beta-alanine for four weeks, their maximal voluntary isometric-contraction strength improved. So taking beta- alanine will likely help with local muscle endurance and improved time under tension when in the gym, which can lead to greater muscle growth.
REFERENCE: Sale C, et al., J Int Soc Sports Nutr. 14;9(1):June 26, 2012.