Influence of oral beta-alanine and L-Histidine supplementation on the carnosine
content of gluteus medius.
Excerpt from above abstract: "Changes in
muscle carnosine concentration appeared to be influenced by beta-alanine
bioavailability. Individual increases in muscle carnosine concentration were
significantly correlated with individual changes in beta-alanine..."
~vs~
High levels of dietary carnosine are associated with
increased concentrations of carnosine and histidine in rat soleus muscle.
Excerpt taken from above abstract: "After 8 wk, 1.8% carnosine resulted
in significant fivefold increases in carnosine and twofold increases in
histidine in the soleus muscle (P < or = 0.05). Muscle vitamin E
concentrations were not significantly affected by dietary carnosine. Thus, very
high levels of dietary carnosine are associated with increases in carnosine and
histidine concentrations in rat soleus muscle."
The carnosine
content of vastus lateralis is elevated in resistance-trained bodybuilders.
J Strength Cond Res. 2005 Nov;19(4):725-729
Tallon MJ, Harris
RC, Boobis LH, Fallowfield JL, Wise JA.
School of Sports, Exercise and
Health Sciences, University College Chichester, Chichester, West Sussex, United
Kingdom.
Tallon, M.J., R.C. Harris, L.H. Boobis, J.L. Fallowfield, and
J.A. Wise. The carnosine content of vastus lateralis is elevated in
resistance-trained bodybuilders. J. Strength Cond. Res. 19(4):725-729.
2005.-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.
Some
recent research in respect to cyclists and beta-alanine supplementation.
Influence of beta-alanine supplementation on skeletal muscle carnosine
concentrations and high intensity cycling capacity.Hill CA, Harris RC, Kim HJ,
Harris BD, Sale C, Boobis LH, Kim CK, Wise JA.
School of Sports, Exercise
& Health Sciences, University of Chichester, Chichester, U.K..
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 TWD with supplementation followed the increase
in muscle carnosine