In previous posts about beta-alanine we have already discussed its main function in the synthesis of muscle carnosine and its role as a buffering agent in intracellular pH, counteracting muscle acidosis and thereby delaying fatigue in sports practice, especially in intermittent or continuous high-intensity disciplines in which the glycolytic pathway predominates (1-4 min; see Figure 1). Beta-alanine also has functions beyond sport.
In this post we will focus and try to address and give answers one by one to the different variables that we must take into account in order to optimize the supplementation of this buffer effectively (just as we did with sodium bicarbonate in previous posts).
It is known that carnosine is a dipeptide formed by Beta-alanine and L-histidine, so we might think that supplementation together with the amino acid L-histidine could improve its synthesis and increase its concentration at the muscle level. But physiology is often not 2+2=4. Concluding from current evidence, this practice does not present additional benefits vs supplementing with beta-alanine alone.
Since histidine is found in a high concentration at the muscle level and has a low affinity for carnosine synthase (the enzyme responsible for the synthesis of carnosine). Beta-alanine, on the other hand, is found in low concentration at the muscle level and has a high affinity for this enzyme, making the latter ultimately the limiting step in this reaction.
Carnosine supplementation itself has also been found to be not beneficial due to its low bioavailability because of the action of carnosinase (enzyme responsible for the degradation of this dipeptide), so carnosine is rapidly degraded in the gastrointestinal tract, making its supplementation ineffective for increasing muscle-level stores
Regarding dose and duration, evidence supports 4-6 g (65mg/kg) in divided doses for at least 28 days. After 10 weeks, muscle carnosine stores may increase by 60-80%. Chronic supplementation (4 weeks – 24 weeks) is the most effective approach and can raise muscle carnosine concentrations by up to 200% (vegetarians and women have lower muscle levels). After supplementation stops, the “washout” period lasts several weeks or months before levels return to approximately their pre-supplementation values.
There is a great variability in the magnitude of this response (59%-200%) during chronic supplementation, with variable responses likely due to a combination of modifiable factors (dose, duration, complementary supplementation, etc…) and non-modifiable (age, sex, disease).
Higher doses and/or a longer supplementation period lead to a greater accumulation of muscle carnosine . Although, as we will see later, higher doses of beta-alanine taken acutely may pose a problem in terms of adverse effects.
The safe doses for ingesting beta-alanine are to distribute approximately 800–1,600 mg every 3–4 h throughout the day to reduce the incidence and severity of paresthesia (an uncomfortable tingling sensation on the skin that can last up to an hour). Another existing solution is the use of slow-release formulas, allowing supplementation with a higher amount without adverse effects and causing greater carnosine retention at the muscle level.
Regarding co-ingestion with meals, it has been shown that the intake of beta-alanine along with carbohydrates or a meal rich in them can lead to greater increases in muscle carnosine than taking beta-alanine between meals due to insulin release mediated by CH, increased translocation of the Na+/K+ ATPase (caffeine can also exert this effect), and exerting greater activity of the TauT transporter (a transporter of vital importance at the muscular level) SEE FIGURE 2.
Another of the supplements that can exert a synergistic effect and that has been verified through the available literature would be sodium bicarbonate (extracellular buffer) and creatine monohydrate (improving the phosphagen pathway).
Other studies have seen how there were different values of muscle carnosine depending on the type of sports discipline, with higher values in bodybuilders and trained sprinters. It is not clear whether this is due to genetic predisposition, an adaptive response to training or differences in the composition of muscle fiber type (with a higher content of muscle carnosine in type II glycolytic fibers compared to type I oxidative fibers).
As a conclusion, these are some of the variables to take into account in order to correctly optimize Beta-alanine supplementation with the aim of increasing carnosine content at the muscle level (SEE FIGURE 3)
BIBLIOGRAPHY
- Trexler ET, Smith-Ryan AE, Stout JR, Hoffman JR, Wilborn CD, Sale C, et al. International Society of Sports Nutrition position stand: Beta-Alanine. J Int Soc Sports Nutr. (2015) 12:30.
- Varanoske AN, Hoffman JR, Church DD, Coker NA, Baker KM, Dodd SJ, et al. Comparison of sustained-release and rapid-release β-alanine formulations on changes in skeletal muscle carnosine and histidine content and isometric performance following a muscle-damaging protocol. Amino Acids. (2018)
- Saunders B, DE Salles Painelli V, DE Oliveira LF, DA Eira Silva V, DA Silva RP, Riani L, et al. Twenty-four weeks of β-alanine supplementation on carnosine content, related genes, and exercise. Med Sci Sports Exerc. (2017)
- Dolan, E., Swinton, P. A., Painelli, V. S., Stephens Semingway, B., Mazzolani, B., Infante Smaira, F., Saunders, B., Artioli, G. G. & Gualano, B. 2019. A Systematic Risk Assessment and Meta-Analysis on the Use of Oral beta-Alanine Supplementation. Adv Nutr.
- Perim, P., Marticorena, F. M., Ribeiro, F., Barreto, G., Gobbi, N., Kerksick, C. M., … & Saunders, B. (2019). Can the skeletal muscle carnosine response to beta-alanine supplementation be optimised?. Frontiers in Nutrition, 6, 135.
AUTHOR
Marcos Rueda Córdoba
- Graduate in Human Nutrition and Dietetics (UGR) and Official Master's in Nutrition in Physical Activity and Sport (UCAM). ISAK I Anthropometrist, Content creator and specialized courses in sports nutrition through online and in-person platforms. Teacher at Grupo San Valero (San Jorge University, Zaragoza)
- In-person Nutrition Consultation in Granada and online
