beta-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis

Author(s)

Saunders, Bryan ; Elliott-Sale, Kirsty ; Artioli, Guilherme G. ; Swinton, Paul A. ; Dolan, Eimear ; Roschel, Hamilton ; Sale, Craig ; Gualano, Bruno

• Document type: Review article
• Source: BRITISH JOURNAL OF SPORTS MEDICINE; v. 51, n. 8, p. 658+, APR 2017.
• Web of Science Citations: 33

Abstract

Objective To conduct a systematic review and meta-analysis of the evidence on the effects of beta-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 ('beta-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 beta-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 beta-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 beta-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 beta-alanine supplementation based on their chosen exercise modality. (AU)

• FAPESP's process: 14/11948-8 - Life without carnosine: development and characterization of a KO rat model for studying the physiological role of carnosine and its implications to physical exercise and muscle metabolism
• Grantee: Guilherme Giannini Artioli
• Support type: Research Grants - Young Investigators Grants
• FAPESP's process: 13/14746-4 - Carnosine metabolism in skeletal muscle: a multi-approach study
• Grantee: Bruno Gualano
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 15/11328-2 - Carnosine metabolism in skeletal muscle: a multi-approach study. Substudy 3: exploring carnosine role in skeletal muscle
• Grantee: Eimear Bernadette Dolan
• Support type: Scholarships in Brazil - Post-Doctorate