Influence of beta-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity.
Muscle carnosine synthesis is limited by the availability of beta-alanine. Thirteen male subjects were supplemented with beta-alanine (CarnoSyn) 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 (Wmax). 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.
Hill
C A
CA
School of Sports, Exercise & Health Sciences, University of Chichester, Chichester, UK.
Harris
R C
RC
Kim
H J
HJ
Harris
B D
BD
Sale
C
C
Boobis
L H
LH
Kim
C K
CK
Wise
J A
JA
D000328:Adult; D001706:Biopsy; D002336:Carnosine / Q000096:biosynthesis* / Q000378:metabolism; D019587:Dietary Supplements; D004334:Drug Administration Schedule; D005080:Exercise Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D011522:Protons; D013654:Taurine / Q000378:metabolism; D013997:Time Factors; D015091:beta-Alanine / Q000008:administration & dosage* / Q000494:pharmacology*
D011522:Protons; D015091:beta-Alanine; D013654:Taurine; D002336:Carnosine