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Extracellular buffering supplements to improve exercise capacity and performance: a comprehensive systematic review and meta-analysis.

Farias de Oliveira, Luana; Dolan, Eimear; Swinton, Paul A.; Durkalec-Michalski, Krzysztof; Artioli, Guilherme G.; McNaughton, Lars R.; Saunders, Bryan


Luana Farias de Oliveira

Eimear Dolan

Krzysztof Durkalec-Michalski

Guilherme G. Artioli

Lars R. McNaughton

Bryan Saunders


Extracellular buffering supplements (sodium bicarbonate [SB], sodium citrate [SC], sodium/calcium lactate [SL/CL]) are ergogenic supplements though questions remain about factors which may modify their effect. The aim of this study was to quantify the main effect of extracellular buffering agents on exercise outcomes and to investigate the influence of potential moderators on this effect, using a systematic review and meta-analytic approach. This study was designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Three databases were searched for articles, which were screened according to inclusion/exclusion criteria. Bayesian hierarchical meta-analysis and meta-regression models were used to investigate pooled effects of supplementation and moderating effects of a range of factors on exercise and biomarker responses. 189 articles with 2019 participants were included, 158 involving SB supplementation, 30 with SC, and seven with CL/SL; four studies provided a combination of buffering supplements together. Supplementation led to a mean estimated increase in blood bicarbonate of +5.2 mmol/L-1 [95%CrI: 4.7 to 5.7 mmol/L-1]. The meta-analysis models identified a positive overall effect of supplementation on exercise capacity and performance compared to placebo (ES0.5 = 0.17 [95%CrI: 0.12 to 0.21]) with potential moderating effects of exercise type, duration and mode, training status and when the exercise test was performed following prior exercise. The greatest ergogenic effects were shown for exercise durations of 0.5–10 min (ES0.5=0.18 [0.13–0.24]) and > 10 min (ES0.5=0.22 [0.10–0.33]). Evidence of greater effects on exercise were obtained when blood bicarbonate increases were medium (4–6 mmol/L-1) and large ( > 6 mmol/L-1) compared with small ( ≤ 4 mmol/L-1) (βSmall:Medium=0.16 [95%CrI: 0.02–0.32], βSmall:Large=0.13 [95%CrI: -0.03–0.29]). SB (192 outcomes) was more effective for performance compared to SC (39 outcomes) (βSC:SB = 0.10 [95%CrI: -0.02 to 0.22]). The study therefore found that extracellular buffering supplements generate large increases in blood bicarbonate concentration leading to positive overall effects on exercise, with sodium bicarbonate being most effective. Evidence for several group-level moderating factors were identified. These data can guide an athlete's decision as to whether supplementation with buffering agents might be beneficial for their specific aims.


FARIAS DE OLIVEIRA, L., DOLAN, E., SWINTON, P.A., DURKALEC-MICHALSKI, K., ARTIOLI, G.G., MCNAUGHTON, L.R. and SAUNDERS, B. 2022. Extracellular buffering supplements to improve exercise capacity and performance: a comprehensive systematic review and meta-analysis. Sports medicine [online], 52(3), pages 505-526. Available from:

Journal Article Type Review
Acceptance Date Sep 23, 2021
Online Publication Date Oct 23, 2021
Publication Date Mar 31, 2022
Deposit Date Oct 20, 2021
Publicly Available Date Oct 24, 2022
Journal Sports medicine
Print ISSN 0112-1642
Electronic ISSN 1179-2035
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Volume 52
Issue 3
Pages 505-526
Keywords Buffering; Supplements; Exercise capacity; Sport performance; Sodium bicarbonate
Public URL
Additional Information The file accompanying this record includes all tables and supplementary materials at the end.