INTRODUCTION: 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. PURPOSE: 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%). METHODS: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). RESULTS: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. CONCLUSIONS: 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.
RCT Entities:
INTRODUCTION: 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. PURPOSE: 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%). METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.
Authors: Bryan Saunders; Mariana Franchi; Luana Farias de Oliveira; Vinicius da Eira Silva; Rafael Pires da Silva; Vitor de Salles Painelli; Luiz Augusto Riani Costa; Craig Sale; Roger Charles Harris; Hamilton Roschel; Guilherme Giannini Artioli; Bruno Gualano Journal: Eur J Nutr Date: 2018-12-14 Impact factor: 5.614
Authors: Michael J Cripps; Katie Hanna; Charlie Lavilla; Sophie R Sayers; Paul W Caton; Craig Sims; Luigi De Girolamo; Craig Sale; Mark D Turner Journal: Sci Rep Date: 2017-10-17 Impact factor: 4.379
Authors: Victor H Carvalho; Ana H S Oliveira; Luana F de Oliveira; Rafael P da Silva; Paolo Di Mascio; Bruno Gualano; Guilherme G Artioli; Marisa H G Medeiros Journal: Redox Biol Date: 2018-07-18 Impact factor: 11.799
Authors: E Dolan; B Saunders; W S Dantas; I H Murai; H Roschel; G G Artioli; R Harris; J E P W Bicudo; C Sale; B Gualano Journal: Sci Rep Date: 2018-10-03 Impact factor: 4.379
Authors: Pedro Perim; Felipe Miguel Marticorena; Felipe Ribeiro; Gabriel Barreto; Nathan Gobbi; Chad Kerksick; Eimear Dolan; Bryan Saunders Journal: Front Nutr Date: 2019-08-27