I am going to use published research to show how this works...
But in short beta-Alanine is in high demand and when present is pulled into muscle and linked to histidine to create
Carnosine. Carnosine supplementation requires splitting the histidine/beta-Alanine link and is twice as expensive. beta-Alanine by itself is needed for this effect.
Physiological role of carnosine in contracting muscle. Int J Sport Nutr Exerc Metab. 2005 Oct;15(5):493-514. Links
Begum G, Cunliffe A, Leveritt M.
High-intensity exercise leads to reductions in muscle substrates (ATP, PCr6, and glycogen) and a subsequent accumulation of metabolites (ADP, P, H(+), and Mg(+)) with a possible increase in free radical production.
These factors independently and collectively have deleterious effects on muscle, with significant repercussions on high-intensity performance or training sessions. The effect of carnosine on overcoming muscle fatigue appears to be related to its ability to buffer the increased H(+) concentration following high-intensity work. Carnosine, however, has other roles such as an antioxidant, a metal chelator, a Ca(2+) and enzyme regulator, an inhibitor of protein glycosylation and protein-protein cross-linking. High level of skeletal muscle carnosine contributes to the latter half of exercise performance during 30-s maximal cycle ergometer sprinting. Jpn J Physiol. 2002 Apr;52(2):199-205. Links
Suzuki Y, Ito O, Mukai N, Takahashi H, Takamatsu K.
The histidine-containing dipeptide carnosine (beta-alanyl-L-histidine) has been shown to significantly contribute to the physicochemical buffering in skeletal muscles, which maintains acid-base balance when a large quantity of H(+) is produced in association with lactic acid accumulation during high-intensity exercise. The purpose of the present study was to examine the relations among the skeletal muscle carnosine concentration, fiber-type distribution, and high-intensity exercise performance. The subjects were 11 healthy men. Muscle biopsy samples were taken from the vastus lateralis at rest. The carnosine concentration was determined by the use of an amino acid autoanalyzer. The fiber-type distribution was determined by the staining intensity of myosin adenosinetriphosphatase. The high-intensity exercise performance was assessed by the use of 30-s maximal cycle ergometer sprinting. A significant correlation was demonstrated between the carnosine concentration and the type IIX fiber composition (r=0.646, p<0.05). The carnosine concentration was significantly correlated with the mean power per body mass (r=0.785, p<0.01) during the 30-s sprinting. When dividing the sprinting into 6 phases (0-5, 6-10, 11-15, 16-20, 21-25, 26-30 s), significant correlations were observed between the carnosine concentration and the mean power per body mass of the final 2 phases (21-25 s: r=0.694, p<0.05; 26-30 s: r=0.660, p<0.05).
These results indicated that the carnosine concentration could be an important factor in determining the high-intensity exercise performance. The carnosine content of vastus lateralis is elevated in resistance-trained bodybuilders.
J Strength Cond Res. 2005 Nov;19(4):725-9.
Tallon MJ, Harris RC, Boobis LH, Fallowfield JL, Wise JA.
Resistance training is associated with periods of acute intracellular hypoxia with increased H(+) production and low intramuscular pH. The aim of this study was to investigate the possible adaptive response in muscle carnosine (beta-alanyl-L-histidine) in bodybuilders. Extracts of biopsies of m. vastus lateralis of 6 national-level competitive bodybuilders and 6 age-matched untrained but moderately active healthy subjects were analyzed by high-performance liquid chromatography. Significant differences were shown in carnosine (p < 0.001) and histidine (p < 0.05). Muscle carnosine in bodybuilders was twice that in controls. The carnosine contents measured are the highest recorded in human muscle and represent a 20% contribution to muscle buffering capacity. Taurine was 38% lower in bodybuilders, though the difference was not significant. Possible causes for the changes observed are prolonged repetitive exposure to low muscle pH, change of diet or dietary supplement use, or the use of anabolic steroids.
The increase in buffering capacity could influence the ability to carry out intense muscular activity.
The absorption of orally supplied beta-alanine and its effect on muscle carnosine synthesis in human vastus lateralis
Amino Acids. 2006 May;30(3):279-89. Epub 2006 Mar 24.
Harris RC, Tallon MJ, Dunnett M, Boobis L, Coakley J, Kim HJ, Fallowfield JL, Hill CA, Sale C, Wise JA.
beta-Alanine in blood-plasma when administered as A) histidine dipeptides (equivalent to 40 mg . kg(-1) bwt of beta-alanine) in chicken broth, or B) 10, C) 20 and D) 40 mg . kg(-1) bwt beta-alanine (CarnoSyntrade mark, NAI, USA), peaked at 428 +/- SE 66, 47 +/- 13, 374 +/- 68 and 833 +/- 43 microM. Concentrations regained baseline at 2 h. Carnosine was not detected in plasma with A) although traces of this and anserine were found in urine. Loss of beta-alanine in urine with B) to D) was <5%. Plasma taurine was increased by beta-alanine ingestion but this did not result in any increased loss via urine. Pharmacodynamics were further investigated with 3 x B) per day given for 15 d.
Dietary supplementation with I) 3.2 and II) 6.4 g . d(-1) beta-alanine (as multiple doses of 400 or 800 mg) or III) L-carnosine (isomolar to II) for 4 w
resulted in significant increases in muscle carnosine estimated at 42.1, 64.2 and 65.8%. Influence of beta-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids. 2006 Jul 28; [Epub ahead of print]
Hill CA, Harris RC, Kim HJ, Harris BD, Sale C, Boobis LH, Kim CK, Wise JA.
Muscle carnosine synthesis is limited by the availability of beta-alanine. Thirteen male subjects were supplemented with beta-alanine (CarnoSyntrade mark) for 4 wks, 8 of these for 10 wks. A biopsy of the vastus lateralis was obtained from 6 of the 8 at 0, 4 and 10 wks. Subjects undertook a cycle capacity test to determine total work done (TWD) at 110% (CCT(110%)) of their maximum power (W(max)). Twelve matched subjects received a placebo. Eleven of these completed the CCT(110%) at 0 and 4 wks, and 8, 10 wks. Muscle biopsies were obtained from 5 of the 8 and one additional subject.
Muscle carnosine was significantly increased by +58.8% and +80.1% after 4 and 10 wks beta-alanine supplementation.
Carnosine, initially 1.71 times higher in type IIa fibres, increased equally in both type I and IIa fibres. No increase was seen in control subjects. Taurine was unchanged by 10 wks of supplementation.
4 wks beta-alanine supplementation resulted in a significant increase in TWD (+13.0%); with a further +3.2% increase at 10 wks. TWD was unchanged at 4 and 10 wks in the control subjects.
The increase in Total Work Done with supplementation followed the increase in muscle carnosine.
<message edited by danmirage on Wednesday, August 30, 2006 7:57 PM>