Objective: To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance.
Design: This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data.
Data sources: 3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms ('β-alanine' and 'Beta-alanine' combined with 'supplementation', 'exercise', 'training', 'athlete', 'performance' and 'carnosine').
Eligibility criteria for selecting studies: Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-analyses.
Results: 40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5-10 min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI -0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64)).
Summary/conclusions: β-alanine had a significant overall effect while subgroup analyses revealed a number of modifying factors. These data allow individuals to make informed decisions as to the likelihood of an ergogenic effect with β-alanine supplementation based on their chosen exercise modality.
Keywords: Amino acids; Exercise; Meta-analysis; Supplements.
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Chung W, Baguet A, Bex T, Bishop DJ, Derave W. Chung W, et al. Int J Sport Nutr Exerc Metab. 2014 Jun;24(3):315-24. doi: 10.1123/ijsnem.2013-0125. Epub 2014 Jan 17. Int J Sport Nutr Exerc Metab. 2014. PMID: 24457999 Clinical Trial.
Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Hobson RM, et al. Amino Acids. 2012 Jul;43(1):25-37. doi: 10.1007/s00726-011-1200-z. Epub 2012 Jan 24. Amino Acids. 2012. PMID: 22270875 Free PMC article.
Danaher J, Gerber T, Wellard RM, Stathis CG. Danaher J, et al. Eur J Appl Physiol. 2014 Aug;114(8):1715-24. doi: 10.1007/s00421-014-2895-9. Epub 2014 May 16. Eur J Appl Physiol. 2014. PMID: 24832191 Free PMC article. Clinical Trial.
Berti Zanella P, Donner Alves F, Guerini de Souza C. Berti Zanella P, et al. J Sports Med Phys Fitness. 2017 Sep;57(9):1132-1141. doi: 10.23736/S0022-4707.16.06582-8. Epub 2016 Jul 5. J Sports Med Phys Fitness. 2017. PMID: 27377257 Review.
Bellinger PM. Bellinger PM. J Strength Cond Res. 2014 Jun;28(6):1751-70. doi: 10.1519/JSC.0000000000000327. J Strength Cond Res. 2014. PMID: 24276304 Review.
Pérez-Piñero S, Ramos-Campo DJ, López-Román FJ, Ortolano R, Torregrosa-García A, Luque-Rubia AJ, Ibáñez-Soroa N, Andreu-Caravaca L, Ávila-Gandía V. Pérez-Piñero S, et al. PLoS One. 2024 Sep 3;19(9):e0309404. doi: 10.1371/journal.pone.0309404. eCollection 2024. PLoS One. 2024. PMID: 39226288 Free PMC article. Clinical Trial.
Harlow J, Blodgett K, Stedman J, Pojednic R. Harlow J, et al. Nutrients. 2024 Aug 17;16(16):2746. doi: 10.3390/nu16162746. Nutrients. 2024. PMID: 39203882 Free PMC article. Review.
García-Durán J, González-Jurado JA, Sánchez-Oliver AJ. García-Durán J, et al. Nutrients. 2024 Aug 4;16(15):2563. doi: 10.3390/nu16152563. Nutrients. 2024. PMID: 39125442 Free PMC article.
Guo W, Wang S. Guo W, et al. Sci Rep. 2024 Jul 22;14(1):16833. doi: 10.1038/s41598-024-67974-y. Sci Rep. 2024. PMID: 39039103 Free PMC article. Clinical Trial.
Zhou Y, Liu X, Qi Z, Yang L, Huang C, Lin D. Zhou Y, et al. Molecules. 2024 May 9;29(10):2216. doi: 10.3390/molecules29102216. Molecules. 2024. PMID: 38792078 Free PMC article.