By James Collier BSc (Hons), Nutrition Consultant and Iain Kendrick BSc MSc (aka iaink), MuscleTalk Moderator
Beta-alanine is an amino acid which has become a very popular addition to pre-workout formulas as it has been found to be a great performance booster. There are so many performance boosting supplements touted to be the next revolutionary thing, but few are actually backed both by solid peer reviewed research as well as strong anecdotal reports of effectiveness. Beta-alanine is an exception; there's good research and its popularity as a performance booster demonstrates the fact that it is a worthwhile inclusion to a supplement stack. How it works is quite complex however, but understanding this will help you get the most out of supplementing with it.
Where is beta-alanine found naturally?
Beta-alanine is a naturally occurring amino acid, but is not found in food on its own, but as part of peptides like carnosine, anserine and balenine, which we consume from meat, fish and poultry. Our bodies can also synthesise beta-alanine from the breakdown of nucleotides. Also, more recently, we can obtain beta-alanine in dietary supplements.
How beta-alanine works
Anaerobic metabolism is where energy is derived without oxygen. Of interest to those who train this occurs in muscles when we exercise. The resulting end product in anaerobic metabolism in muscles is lactic acid, and this can result in a drop in pH within the muscle, i.e. the muscle becomes more 'acidic'. This state of 'acidosis' is actually reached when there is a miss-match between anaerobic and aerobic energy metabolism and the resultant lactic acid accumulates within the muscles. This then disassociates into hydrogen ions (H+) and lactate. It is this release of the H+ that causes the drop in pH of the muscle cell. The measure of pH is itself really a measure of H+ within a solution. In fact it is the inverse log of the H+ concentrations; essentially a mathematical way of showing a large number as a smaller number, and the 'inverse' part means that as concentrations rise, the pH drops.
When levels of lactic acid are high enough it interferes with energy metabolism and muscle fibre contraction and signifies failure and the end of a set. This sequence of events is often incorrectly thought of as being the result of the build up of lactate in a muscle, as measures of lactate are used to indirectly estimate pH levels in the blood and muscle, but as described above, it's actually the build up of H+ that produces contributes to temporary muscular fatigue.
Resistance weight training is predominantly an anaerobic form of exercise. Beta-alanine has been shown to have a positive effect on anaerobic endurance through its ability to enable increased 'buffering' of H+ and therefore delay the onset of lactic acidosis in the muscle cell.
You can now see that supplementation with the amino acid beta-alanine potentially allows you to perform more work and more reps before you reach muscular failure. However, it is actually more complex than this. Beta-alanine's action is indirect through a substrate known as carnosine. Carnosine is a naturally occurring dipeptide synthesised from the amino acids beta-alanine and histidine. After beta-alanine is ingested it is converted to carnosine in the body and it is actually the carnosine which is responsible for the buffering of the H+.
Carnosine is found in both type I and type II muscle fibres, but in significantly higher concentrations in type II fibres, the type primarily used in high intensity strength workouts and the type most responsive to muscular growth (Harris et al 1998). It is therefore also the fibre type most dependent on anaerobic metabolism and hence must have a greater resistance to changes in pH.
Indeed, carnosine has been used as a sports supplement in the past for athletes, but as a supplement it didn't really catch on mainly because it really wasn't all that effective. Supplementary carnosine is actually less efficient at raising carnosine concentrations due to the fact that the body actually breaks down ingested carnosine into beta-alanine and histidine before re-synthesizing these two amino acids back into carnosine. Carnosine was infact first identified in 1900, and in 1938 its role as a muscle buffer was described.
The majority of recent research has used beta-alanine supplementation to raise carnosine stores within the muscle. Kendrick et al (2009) looked at carnosine levels in skeletal muscle fibres following beta-alanine supplementation. They found a significant increase in carnosine content of muscle fibres with beta alanine supplementation, both type I and II fibres.
Researchers have shown that when supplementing with beta-alanine for just 4 weeks, carnosine concentration increases by approx. 40-60% (Harris et al 2006; Hill et al 2007). Supplementing with beta-alanine for 10-12 weeks showed carnosine concentrations increased by up to 80% (Hill et al 2007). This is a tremendous increase in an important intracellular buffer.
The effects of beta-alanine in raising blood carnosine levels are longer term and beta-alanine should be taken daily, not just pre-workout. However, there may be a positive effect from taking beta-alanine acutely, i.e. immediately pre-workout, in that there is a psycho-somatic effect in that the flushing effect gives more of a positive feeling and well-being helping boost psychological performance which may transfer into improved physical performance.
Research has indicated that the optimal dose for beta-alanine supplementation is approximately 6g per day (Harris et al 2006; Hill et al 2007; Kendrick at al 2008; Ponte et al 2007); this level significantly boosts carnosine levels and improves performance. The most recent research, now using 4-5g a day, is showing comparable carnosine concentration and performance improvements to those using 6.4 g daily (Baquet et al 2009).
Some people recommend an optional 2 week loading phase of 6g per day during the first month of use followed by 4g per day thereafter. However, it's not so much daily dose which is important, as weekly dosage is more critical for attaining an optimal carnosine level. Taking less on non-training days is fine, as long as you make up for this on training days so there is an average dose of 4-6g per day over the week.
How long will it take to start noticing benefits?
Generally, improved performance can be noted in as little as two weeks, although people claim benefits within one week. As carnosine levels increase, the benefits will follow. It is typically after 3-4 weeks that most benefits are felt, but research has also shown that carnosine levels continue to increase for a minimum of 12 weeks so it is recommended to continue using beta-alanine for at least three months to optimise carnosine levels.
There are also the immediate benefits which many users experience. These happen soon after ingestion and include intense vasodilatation and muscle pumps from the very first dose of beta-alanine. This may be because carnosine is a powerful precursor in generating the enzyme nitric oxide synthase necessary for making the powerful vasodilator nitric oxide. In addition, some people report that they like the flushing feeling from beta-alanine and this can psychologically boost performance.
Beta-alanine side effects and safety
One side effect of beta-alanine supplementation is a tingly flushing sensation which causes a few minutes after ingestion. The face, particularly around the lips, is particularly sensitive and could be described as like 'pins & needles'. The sensation is known as paresthesia and thought to be the effect of beta-alanine binding with nerves under the skin. Some people find the sensation strangely pleasant and claim it helps them feel 'fired-up' which enhances their workout. However, others find the paresthesia unpleasant and hard to tolerate although it is completely harmless. The sensation does decrease with continued use as you become 'used' to the supplement and it can also be lessened by taking it after food (especially carbs). The paresthesia also typically dissipates on the commencement of exercise or strenuous activity. The effect is actually enhanced if beta-alanine is consumed along with caffeine, so pre-workout formulas which contain both can have quite a strong effect. If people do find this unpleasant then it's advisable to spread the dose into smaller amounts throughout the day and consume it with food.
Other than the enhanced performance effect, there are no other side effects of supplementation with beta-alanine and research has also shown it to be completely safe.
Is beta-alanine supplementation worth considering?
Supplementing with beta-alanine leads to an increase in muscle carnosine concentrations. Carnosine helps to soak up the excess H+, which in turn can reduce the onset of muscular acidosis and time to fatigue. Beta-alanine is a very exciting and promising workout aid supplement, and should be particularly beneficial to those that weight train using higher reps, combined with short rest periods and moderate to high volume sessions. It should be used daily either on its own or as part of a pre-workout stack, and beta-alanine supplementation should be extremely useful in delaying the onset of fatigue.
- Baquet A, et al (2009). Carnosine loading and washout in human skeletal muscles. J Appl Physiol 106(3):837-42.
- Harris RC, M Dunnett, PL Greenhaff (1998). Carnosine and taurine contents in individual fibres of human vastus alteralis muscle. J Sports Sci 16:639-643.
- Harris RC, et al (2006). The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino Acids. 30:279-289, 2006.
- Hill, CC, et al (2007). Influence of β-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids 32:225-233.
- Kendrick IP, et al (2008). The effects of 10 weeks of resistance training combined with β-alanine supplementation on whole body strength, force production, muscular endurance and body composition. /em>Amino Acids 34(4):547-54.
- Kendrick IP, et al (2009). The effect of 4 weeks beta-alanine supplementation and isokinetic training on carnosine concentrations in type I and II human skeletal muscle fibres. Eur J Appl Physiol DOI: 10.1007/s00421-009-0998-5
- Ponte J, et al (2007). Effect of 14-28 days of β-alanine supplementation on isometric endurance of the knee extensors. J Sport Sci 25:334.