In previous posts about beta alanine we have already commented on its main function in the synthesis of muscle carnosine and its role as a buffer / buffer agent in intracellular pH, counteracting muscle acidosis and thereby delaying fatigue in sports practice especially in disciplines intermittent or continuous high intensity with predominance of the glycolytic pathway (1-4min) SEE FIGURE 1. In addition to many other functions beyond the sports field.
In this publication we will focus and try to address and respond one by one to the different variables that we must consider in order to optimize the supplementation of this buffer effectively (as we did with sodium bicarbonate in previous publications).
It is known that carnosine is a dipeptide formed by Beta alanine and L-histidine, so we might think that supplementation with the amino acid L-histidine could improve its synthesis and increase its concentration at the muscular level. But physiology is often not 2 + 2 = 4. Concluding the current evidence that this practice has no additional benefits vs. supplementing with beta alanine alone.
Since histidine is found in a high amount at the muscular level and has a low affinity for carnosine synthase (enzyme responsible for the synthesis of carnosine). B-alanine on the other hand is in low concentration at the muscular level and has a high affinity for this enzyme, the latter being finally the limiting step in this reaction.
Carnosine supplementation itself has also proved not to be beneficial due to its low bioavailability due to the action of carnosinase, carnosine is rapidly degraded in the gastrointestinal tract, its supplementation being ineffective to increase muscle level deposits
Regarding the doses and duration of the supplementation, it has been seen that the general recommendations are 4-6 g (65mg / kg) in divided doses for a minimum period of 28 days, in 10 weeks it is increased (60-80%). Carnosine deposits The most effective being a chronic supplementation (4 weeks – 24 weeks) sufficient to reach 200% concentration of muscle carnosine (vegetarians and females have lower muscle level). The “Washout” or non-intake of supplementation takes several weeks or months before returning to similar levels of pre-supplementation.
There is a great variability in the magnitude of this response (59% -200%) during chronic supplementation, it being probable that the variable responses are due to a combination of modifiable factors (dose, duration, complementary supplementation, etc …) and non-modifiable (age, sex, disease).
Higher doses and / or a longer period of supplementation lead to a greater accumulation of muscle carnosine. Although as we will see later, higher doses of beta alanine ingested acutely can be a problem in terms of adverse effects.
The safe doses for ingestion of beta-alanine is to be taken in divided doses of 800–1,600 mg every 3–4 h during the day to reduce the incidence and severity of paraesthesia (an uncomfortable tingling sensation in the skin that can last up to an hour). Another of the existing solutions is the use of slow-release formulas allowing supplementation with a greater amount without adverse effects and with a greater retention of carnosine at the muscular level.
Regarding the coingesta with meals, it has been proven how the intake of beta alanine with carbohydrates or a meal rich in these can lead to greater increases in muscle carnosine than ingesting beta alanine between meals due to release of insulin mediated by HC increased translocation of Na + / k + ATPase (caffeine can also exert this effect) and exerting greater activity of the TauT transporter (vitally important transporter at the muscular level) SEE FIGURE 2.
Other studies have seen how different values of muscle carnosine existed according to 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 the type of muscle fiber (there is a higher content of muscle carnosine in glycolytic type II fibers compared to oxidative fibers type I).
In conclusion, these are some of the variables to take into account in order to correctly optimize Beta alanine supplementation in order to increase the carnosine content at the muscular level (SEE FIGURE 3)
