However, other research shows that BCAAs may not produce greater muscle gain in those following an exercise program . BCAAs are critically important for muscle growth and make up about 14% of the amino acids in your muscles . While more research on beta-alanine and muscle gain is needed, this supplement may help support muscle gain when combined with an exercise program. Another study reported that adding a beta-alanine supplement to a six-week, high-intensity interval training program increased lean body mass by about 1 pound (0.45 kg) more than a placebo .