Energy is required by the human body for everything from breathing to weightlifting and running, and researchers have found that sprinters tend to have higher levels of muscle carnosine compared to long-distance runners.
Carnosine is a proton buffer that is found in high levels in skeletal muscle tissue, and increasing levels of carnosine in the muscle may be able to enhance athletic performance by preventing excess acid levels in muscle.
Increased levels of carnosine can reduce fatigue and improve total work output when exercising at a high level of intensity.
Carnosine is also used to boost muscle mass for those in the bodybuilding program.
While it does not directly increase muscle protein synthesis, it can enable them to work harder during strength training sessions.
The Carnosine and Beta-Alanine Connection
Taking L-carnosine directly is not recommended because it is quickly depleted from the body when ingested orally.
However, Beta-alanine is an amino acid that has been shown to increase carnosine levels in fast-twitch muscle fibers.
Interest in beta-alanine supplementation as a means for increasing muscle carnosine has been powered by studies demonstrating a positive outcome on exercise performance and capacity.
These studies made use of a variety of models of sustained or intermittent high-intensity exercise, such as rowing, sprint running, sprint cycling, swimming, sustained heavy load carrying, etc…
Synthesis of carnosine, which occurs in muscle, is limited by the availability of beta-alanine obtained. A process that may, in part, depend on vitamin B6, or from the consumption of muscle meat.
In humans, ingested carnosine and other histidine-containing dipeptides are rapidly hydrolyzed to their constituent amino acids, providing a source of dietary-derived beta-alanine.
Research shows that proper oral administration of beta-alanine can increase muscle carnosine levels by as much as 80%.
In multiple human trials, using beta-alanine to elevate muscle carnosine levels resulted in decreased fatigue, increased endurance, greater power output, and improvements to several other performance indicators.
Carnosine is a dipeptide made up of two amino acids, beta-alanine, and histidine.
By combining with beta-alanine, the histidine is prevented from linking with other amino acids to form proteins and, hence, is rendered chemically passive.
This enables large amounts of histidine, which is the buffering component of carnosine, to be accumulated in muscle cells.
Synthesis of carnosine occurs in the muscle cells themselves and is restricted by the supply of beta-alanine.
Although carnosine can be synthesized in the liver, the amount supplied to muscle in humans is very low when compared to our requirement for carnosine.
Eating meat and fish provides an important source of beta-alanine and can double the amount of carnosine in the muscle.
To increase carnosine levels beyond the normal dietary levels obtained through these food sources, supplementation is required.
Compared with other large mammals, humans have an unusually low muscle carnosine level, especially for vegetarians, where synthesis relies solely upon beta-alanine produced in the liver.
Supplementation and Dosages
To naturally achieve very high levels of muscle carnosine, the diet would need to be comprised almost exclusively of meat.
Fortunately, that is no longer necessary with the availability of supplements that are scientifically proven and highly effective.
Studies performed around the world using beta-alanine products have demonstrated that the increase in muscle carnosine is dose-dependent.
It happens in such a way that when supplementing with 6.4g per day, the increase is twice that achieved with 3.2g per day, which itself is twice that achieved with 1.6g per day.
It is thought that eventually a peak in the muscle content may be reached, wherein the increase above the pre-supplementation level is again dose-dependent.
Maintaining this high level of carnosine in muscle requires ongoing supplementation with high enough doses over a continuous period of time, and reducing the supplementation dose, or stopping altogether will result in a gradual decline in the muscle carnosine content to a lower threshold, or right back to the pre-supplementation level.
Supplementation with beta-alanine to increase muscle carnosine is equally effective in males and females, trained and untrained subjects, vegetarians, and non-vegans, as well as in young and older individuals.
Risk of Side Effects
Using beta-alanine to increase muscle carnosine has been shown to work quickly and efficiently, and also, well-tolerated by most users.
The only side effect of concern associated with beta-alanine supplementation is paresthesia.
Paresthesia is a temporary condition that results from taking too much beta-alanine acutely, that may cause the skin to “crawl”, itch or burn.
The paresthesia associated with beta-alanine supplementation goes away on its own within an hour or so and can be avoided by breaking daily doses into several smaller amounts to be taken about 3 hours apart.
Although using a beta-alanine supplement to elevate muscle carnosine is safe for most people, it is best to talk with your doctor before beginning to use any dietary supplements.