What is Beta-Alanine?
Beta-alanine is a non-essential amino acid that classified as a non-proteinogenic amino acid, which means it is not involved in protein synthesis and thus does not naturally occur in proteins as a single amino acid1. By contrast, beta-alanine normally occurs in protein as part of a dipeptide called, carnisine. Carnosine is made up of the two amino acids, beta-alanine and histidine. However, beta-alanine is considered the rate-limiting amino acid for synthesis of carnosine1. This means that the availability of beta-alanine, as opposed to histidine, is the primary factor determining synthesis of carnosine. For this reason, beta-alanine has been extensively researched for its capacity to increase muscle levels of carnosine, which acts as an intra-muscular buffer of acidity2.
Where Does Beta-Alanine Come From?
The major source of beta-alanine is via intake of carnosine from poultry and meat3. Once carnosine is ingested, it is rapidly broken down in the blood to beta-alanine and histidine by an enzyme called carnosinase4. Studies suggest that the average omnivore consumes between 50 to 300mg of carnosine4. Carnosine is 36.5% beta-alanine by weight, which equates to between 18 and 109mg of beta-alanine for the average omnivore5. With meat being the best source of beta-alanine, studies have also shown that vegetarians have 22% lower muscle carnosine levels6.
Beta-Alanine Benefits Beta-alanine has largely been studied for its high-intensity exercise performance-enhancing properties and is fast becoming one of the most popular ergogenic aids for sports performance2. Studies have repeatedly shown that supplementation with Beta Alanine leads to an increase in the carnosine content of both type I and type II muscle fibres1, 7-9.The performance enhancing effects of beta-alanine have largely been studied using various stationary cycling protocols2 because this generally represents the most practical, accurate and cost-effective model for measurement, however, beta-alanine supplementation has also been studied in rowers, runners and bodybuilders2. Studies have typically shown that supplementation with beta-alanine leads to an increase in exercise capacity for maximal exercise intervals of between 1 and 4 mins2. Some studies have also shown that beta-alanine can increase exercise capacity for durations lasting longer than 4 minutes2.