by Chad Kerksick PhD February 01, 2021 6 min read
I wouldn't be surprised if you've overheard someone at your gym talking about beta-alanine.
It's extremely popular, well-conducted studies are available supporting its use, and there is a substantial amount of misinformation regarding its overall role during exercise and training.
An explosion of products containing beta-alanine has ensued, and this is due to the science which has supported its uses .
To start this discussion, I’ll formally introduce beta-alanine, and then attempt to work backwards.
Beta-alanine is an amino acid that is supplied to our bodies from two sources: 1) dietary intake (predominantly meats) and 2) natural production inside our liver. In fact, our liver is the only place in our body that makes beta-alanine.
Beta-alanine is important, because its supply dictates how much carnosine our bodies can make.
"Did you say carnosine? What the heck is that?"
Carnosine is a molecule produced inside our muscles that is one of several key components that act as buffers during situations in which high levels of acid are produced inside our muscles.
In this respect, very intense, stressful exercising scenarios are known to result in high levels of acid production.
So, if you’re following along, carnosine is a key molecule produced in our bodies that helps to counteract the excessive acid production, which occurs during stressful exercise.
This excessive acid production is closely linked to fatigue and a diminished ability of your muscles to contract and perform.
Buffers like carnosine are key components inside our body, which help to regulate the production of waste products and other substrates that can dictate the extent to which you can push yourself during exercise.
In fact, recent studies have suggested that increases in the carnosine content of your muscles is a promising strategy to enhance the total buffering capacity or in other words to better maintain the balance between an acidic, or non-acidic, environment in exercising muscles [2-3].
A relevant question to the point above is, “Why don’t people just supplement with carnosine then instead of beta-alanine?”
I thought that the first time I started reading about carnosine as well. It almost sounded too good to be true.
The second-coming of creatine monohydrate … except our muscles can’t absorb carnosine out of our bloodstream .
So, how does it get it inside the muscles? Carnosine is made of two amino acids, histidine and beta-alanine.
Interestingly, your muscle can’t produce either one of them (beta-alanine is only produced in the liver ), so it has to absorb both of them from the bloodstream.
Therefore, natural production of carnosine inside our muscles is dependent upon the muscles ability to bring in histidine and beta-alanine, so it can produce carnosine.
Remember, the muscle can’t absorb carnosine from the blood, and it can’t produce either of histidine or beta-alanine ... so, unless your muscles get these two building blocks from somewhere else, carnosine supply in your muscles will go down … way down.
And this spells trouble for your ability to repeatedly pound out reps and sets during your workouts.
Furthermore, when evaluating additional highly chemistry-related information, it becomes clear that the rate-limiting step for your body to produce carnosine inside the muscle, is how available the supply of beta-alanine is in the bloodstream [3, 6-7].
It’s important to remember that carnosine functions primarily to help prevent an excessive build-up of acid and waste products in your muscles during exercise, which leads to fatigue and/or a decrease in performance .
Other animals have carnosine in their muscles, and it's cool to find out that a specific species of whale, which will hold its breath for up to 30 min while diving for food, is reported to have the highest amounts of carnosine inside its muscle; an amount which is in fact 25 times greater than what is found in most animals !
Similarly, the carnosine concentrations of racing horses and dogs are seven and two times greater (respectively) than those amounts found in humans .
Why talk about these other animals? All three examples are scenarios which are highly anaerobic or “without oxygen”, and activities such as sprinting (running or cycling) and weight lifting are also predominantly anaerobic as well.
If other highly anaerobic animals have high amounts of carnosine in their muscles, it makes good sense that humans who also participate and compete in similar types of activities should also participate in strategies to maximize the amount of carnosine stored in their muscles as well.
Expectedly, 800-m runners/rowers and experienced bodybuilders (all examples of human athletes that are highly anaerobic, and where excessive acid production may limit performance) were found to have greater buffer capacity and greater levels of carnosine inside their muscles [8-9].
Think about those moments during exercise where you start to feel the "burn". Eventually it becomes too much of a pain, and causes you to stop.
The idea is to slow down and lower the production of acid, which will in turn slow down the rate at which you feel that. This will allow you to push harder, go longer, and perform at a higher level!
The last point I will make relates to the make-up of our muscles.
If you didn't know, there are different types of muscle fibers that exist inside our muscles.
Human muscles have type I and type II muscle fibers, and the most anaerobic fibers are called type II B fibers. In addition, these fibers have tremendous potential to produce force and power.
If you’re putting the pieces together, one would then expect that type II fibers would have a higher concentration of carnosine, and this is exactly what has been found in previous research .
In summary, a great deal of interest has developed over beta-alanine and its ability to enhance exercise performance.
Uniquely, the increased supply of beta-alanine is not the thing to remember, but rather it’s the increased ability of your body to produce carnosine inside the muscles.
Carnosine is an amazing buffer which is able to offset the massive accumulation of acid and waste products inside your muscles that results from regular participation in exercise, whether it’s running or cycling sprints, resistance training for muscle growth with heavy weights, low rest and high reps (sound familiar?) or even in scenarios where you need to finish with a strong burst after you’ve been exercising for a few hours.
For some women, this last scenario would mean trying to beat the lady in the pink hat and matching shorts (and shoes and socks) during a running race.
Whatever your motivation, supplementing with beta-alanine is likely the latest nutritional supplement which researchers have revealed to positively impact performance and your ability to train intensely.