Document Type

Article

Publication Date

2026

DOI

10.1002/ejsc.70225

Publication Title

European Journal of Sport Science

Volume

26

Issue

8

Pages

e70225

Abstract

Sodium bicarbonate positively impacts performance, but its associated gastrointestinal symptoms (GIS) may limit use. This systematic review synthesized literature that has evaluated GIS with sodium bicarbonate supplementation. Literature searches were performed from February 2024-March 2026. Eligible studies provided ≥ 5 g of sodium bicarbonate within a 24-h period or, if a multi-day protocol, at least one day involving ≥ 5 g. Included studies had a placebo group/condition or a comparison group/condition that created a contrast related to delivery method, form, or dose. In total, 101 investigations were summarized in six categories: acute single dosing (n = 35); acute spread dosing (n = 28); chronic dosing (n = 7); acute versus chronic dosing (n = 5); delivery form (n = 18); and other (n = 8). Existing literature suggests that common acute doses (0.2-0.4 g/kg) elicit mild-to-severe GIS, which likely increase in a dose-dependent manner when sodium bicarbonate is ingested in a single dose. Strategies to reduce GIS with acute dosing include spreading intake over hours, using enteric-coated capsules/tablets, and ingesting sodium bicarbonate mini-tablets within a carbohydrate hydrogel. Direct comparisons of these strategies to reduce GIS are absent in current literature; thus, ranking their effectiveness is not possible. Multi-day dosing may lessen GIS, but symptom documentation throughout supplementation periods is poorly characterized. Notably, 26 of 101 studies failed to perform inferential statistical testing to examine condition/group differences in GIS. Making definitive recommendations about sodium bicarbonate supplementation to minimize GIS remains challenging. Major needs remain for direct comparisons between protocols purported to reduce GIS and improvements in GIS data collection, reporting, and analysis.

Rights

© 2026 The Authors.

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Data Availability

Article states: "The authors have nothing to report."

Original Publication Citation

Winter, I. P., Sarac, P., & Wilson, P. B. (2026). Gastrointestinal symptoms associated with sodium bicarbonate supplementation protocols: A systematic review. European Journal of Sport Science, 26(8), Article e70225. https://doi.org/10.1002/ejsc.70225

ORCID

0009-0009-3525-6413 (Winter), 0009-0007-8151-9478 (Sarac), 0000-0003-4052-5023 (Wilson)

Additional Files
ejsc70225-sup-0001-suppl-data.docx (161 kB)
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