Twenty-four Weeks of β-Alanine Supplementation on Carnosine Content, Related Genes, and Exercise.
Skeletal muscle carnosine content can be increased through β-alanine (BA) supplementation, but the maximum increase achievable with supplementation is unknown. No study has investigated the effects of prolonged supplementation on carnosine-related genes or exercise capacity.



This study aimed to investigate the effects of 24 wk of BA supplementation on muscle carnosine content, gene expression, and high-intensity cycling capacity (CCT110%).



Twenty-five active males were supplemented with 6.4 g·d of sustained release BA or placebo for a 24 wk period. Every 4 wk participants provided a muscle biopsy and performed the CCT110%. Biopsies were analyzed for muscle carnosine content and gene expression (CARNS, TauT, ABAT, CNDP2, PHT1, PEPT2, and PAT1).



Carnosine content was increased from baseline at every time point in BA (all P < 0.0001; week 4 = +11.37 ± 7.03 mmol·kg dm, week 8 = +13.88 ± 7.84 mmol·kg dm, week 12 = +16.95 ± 8.54 mmol·kg dm, week 16 = +17.63 ± 8.42 mmol·kg dm, week 20 = +21.20 ± 7.86 mmol·kg dm, and week 24 = +20.15 ± 7.63 mmol·kg dm) but not placebo (all P > 0.05). Maximal increases were +25.66 ± 7.63 mmol·kg dm (range = +17.13 to +41.32 mmol·kg dm), and absolute maximal content was 48.03 ± 8.97 mmol·kg dm (range = 31.79 to 63.92 mmol·kg dm). There was an effect of supplement (P = 0.002) on TauT; no further differences in gene expression were shown. Exercise capacity was improved in BA (P = 0.05) with possible to almost certain improvements across all weeks.



Twenty-four weeks of BA supplementation increased muscle carnosine content and improved high-intensity cycling capacity. The downregulation of TauT suggests it plays an important role in muscle carnosine accumulation with BA supplementation, whereas the variability in changes in muscle carnosine content between individuals suggests that other determinants other than the availability of BA may also bear a major influence on muscle carnosine content.
1Applied Physiology and Nutrition Research Group, University of São Paulo, São Paulo, BRAZIL; 2Junipa Ltd., Newmarket, Suffolk, UNITED KINGDOM; and 3Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement Research Centre, Nottingham Trent University, Nottingham, UNITED KINGDOM.
Bryan
B
Saunders
Vitor
V
DE Salles Painelli
Luana Farias
LF
DE Oliveira
Vinicius
V
DA Eira Silva
Rafael Pires
RP
DA Silva
Luiz
L
Riani
Mariana
M
Franchi
Lívia DE Souza
LS
Gonçalves
Roger Charles
RC
Harris
Hamilton
H
Roschel
Guilherme Giannini
GG
Artioli
Craig
C
Sale
Bruno
B
Gualano
D000328:Adult; D001706:Biopsy; D002336:Carnosine / Q000235:genetics* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements; D015536:Down-Regulation; D015444:Exercise / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015091:beta-Alanine / Q000008:administration & dosage*
D015091:beta-Alanine; D002336:Carnosine