Beta-alanine is the building block of carnosine, a molecule that helps buffer acid in muscles, increasing physical performance in the 60–240-second range. Beta-alanine can aid lean mass gain. Beta-alanine is a modified version of the amino acid alanine. Beta-alanine has been shown to enhance muscular endurance. Many people report being able to perform one or two additional reps in the gym when training in sets of 8–15 repetitions. Beta-alanine supplementation can also improve moderate - to high-intensity cardiovascular exercise performance, like rowing or sprinting. When beta-alanine is ingested, it turns into the molecule carnosine, which acts as an acid buffer in the body. Carnosine is stored in cells and released in response to drops in pH. Increased stores of carnosine can protect against diet-induced drops in pH (which might occur from ketone production in ketosis, for example), as well as offer protection from exercise-induced lactic acid production. Large doses of beta-alanine may cause a tingling feeling called paresthesia. It is a harmless side effect.