It is a dipeptide that results from the condensation of β-alanine and L-histidine. Its quantity within the human body varies according to the distribution of different types of muscle fibres and gender. In more detail, it is known that muscle fibres can be classified into red fibres, known as slow fibres, and white or fast fibres (please note that this subject, for the sake of brevity, is dealt with here in an extremely crude manner). The red fibres are particularly suited to extensive efforts, i.e. not particularly large, but protracted; on the contrary, the white fibres are suited to high intensity, but short duration efforts. Now, the carnosine present in white fibres is double or sometimes even triple that represented in red fibres (Mannion, 1992). Since the distribution of the two fibres is partly modifiable by training, it is not surprising that the habit of intensive loading increases the amount of carnosine in the muscles (because it increases the number of white fibres), which is higher than that of sedentary people; in contrast, the habit of extensive loading reduces it. Athletes specialised in extensive performance have less carnosine than not only power athletes, but also than sedentary people. Carnosine is also more highly represented in the male gender: men’s muscle fibres contain on average 20% more carnosine than women’s muscles. The limiting factor for endogenous carnosine production is the amount of β-alanine in the blood, while that of histidine does not appear to have any influence.

Function

  A study by Suzuki (2002) shows that carnosine has the ability to facilitate the disposal of lactic acid from the muscle site in the context of intensive metabolic loading. It is therefore not surprising that Stout (2005) and Rakes (2005) found an improvement in intensity performance in trials lasting longer than 10-15 seconds. A further function of carnosine could be as an adjuvant to caffeine in its function of increasing the strength of muscle contraction, but this effect remains controversial and to be verified.

Negative notes

  There are no known adverse effects associated with carnosine supplementation.

Form and posology

  Carnosine supplements are mostly available on the market in the form of tablets and soluble powder. A daily intake of 10-16g is recommended. By doing so, you should start to see performance results after about a month.