How does beta-alanine work?

Much of Beta-Alanine’s effects come through boosting the synthesis of an intramuscular dipeptide (two amino acids) called carnosine. To function effectively, muscle cells rely on the powerful intracellular buffer carnosine to avoid becoming acidic (low pH) during exercise. If you want your muscles to remain strong and maintain powerful contractions, they need to be in an optimal pH range. If they don’t and the pH drops below that optimal level, you have significantly less strength and fatigue more quickly.
You know this is happening when you feel that familiar burn in your muscles or even when you’re lifting heavy and reach muscular failure. Muscle pH has dropped and it’s largely a result of an increase in hydrogen ions (H+) which build up when you break down the high energy compound ATP during exercise.The breakdown of ATP and the subsequent rise in H+ concentrations occurs in our all of our energy systems but is most prevalent in an energy system called glycolysis which also produces lactic acid. Lactic acid releases H+ ions, contributing further to the pool of H+ that’s filling your muscles from the breakdown of ATP.

Wouldn’t it be nice to knock out a few more reps? If you had more carnosine in your muscles, you would. When excess H+ are released and build up at a rapid rate from exercise, muscular pH to drops fast. Your body’s natural carnosine levels become overwhelmed and your energy and endurance decline rapidly and your strength suffers.
Carnosine to the rescue. Since hydrogen ions are swarming your muscle cells, whether you feel a burn or not, any added buffering of these ions is the key to keeping your muscles firing. Carnosine does exactly that, naturally absorbing H+ and keeping us closer to the optimal pH range, allowing us to train harder and train longer. Of course, the challenge is that we only have a limited level of naturally stored carnosine in our muscles. With more stored carnosine, you could lift more and lift longer. You would be stronger and most likely bigger, leaner and more muscular. So how can we increase our carnosine levels?

The Beta-Alanine-Carnosine connection.
We can increase our carnosine levels by increasing the ingestion of Beta-Alanine which is one of the two amino acids that make up carnosine. Why not just take straight carnosine? When you ingest carnosine in isolation, most of it is broken down in the gastrointestinal (GI) tract into its constituent amino acids, beta-alanine and histidine. Some intact carnosine does escape the GI tract freely but even that amount is quickly broken down in our blood by the enzyme Carnosinase. In a very short time, all the carnosine you just ingested is either eliminated or converted to beta-alanine and histidine. These two amino acids are then taken into the muscle, where they are converted back to carnosine. This is the key. Unfortunately, only approximately 40% of the carnosine you take actually contains beta-alanine, making it inefficient at best .You are better off, from both efficiency and a financial standpoint, taking Beta-Alanine directly. You would have to take substantially more carnosine just to approach the increased levels of intramuscular carnosine achieved by taking the research supported dose of beta-alanine alone.

Here is why it is so important to use Beta-Alanine in supplement form to concentrate carnosine in your muscles. When you ingest Beta-Alanine, your body transports it into your muscles and with the help of the enzyme carnosine synthetase, combines it with histidine to rebuild carnosine within your muscles.