REF-354 · Hadzic et al., 2019 / Grgic et al., 2020 · Journal of the International Society of Sports Nutrition, · Paper

Sodium bicarbonate and exercise performance

ISSN position stand (Grgic et al. 2021)

Astrong evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

Key Findings (evidence summary)

1

Sodium bicarbonate at 0.2-0.5 g/kg improves performance in muscular-endurance activities, combat sports, and high-intensity cycling, running, swimming and rowing; effects are mostly established for high-intensity tasks lasting 30 s to 12 min

2

Improves both single- and multiple-bout exercise

3

Works in men and women

4

Single dose: 0.2 g/kg is the minimum effective dose; 0.3 g/kg appears optimal; 0.4-0.5 g/kg adds no benefit and more side-effects

5

Single-dose timing: 60-180 min before exercise

6

Multiple-day protocols (3-7 days, 0.4-0.5 g/kg per day, split e.g. 0.1-0.2 g/kg at breakfast, lunch and dinner) also work and can move side-effects away from competition day

7

Long-term use before every training session may enhance training adaptations (time to fatigue, power output)

8

Side-effects — bloating, nausea, vomiting, abdominal pain — vary between and within individuals but are generally low; they can still hurt performance. Mitigation: smaller doses (0.2-0.3 g/kg), ingestion ~180 min before or timed to the individual's response, with a high-carbohydrate meal, or in enteric-coated capsules

9

Combining with creatine or β-alanine may be additive; combination with caffeine or nitrate is unclear

10

Part of the effect appears to be placebo-driven

Practical Application

The ISSN position stand: 0.3 g/kg sodium bicarbonate taken 60-180 min before high-intensity efforts of 30 s to 12 min improves performance (0.2 g/kg is the floor; 0.4-0.5 adds side-effects, not benefit), in single and repeated bouts, in men and women. For an endurance athlete that is a short-TT, hill-repeat, criterium or hard-interval tool — not a marathon or multi-hour ride aid.
Race-day protocol from the stand: single dose 0.2-0.3 g/kg, 60-180 min out; or a 3-7 day serial protocol at 0.4-0.5 g/kg/day split across meals to keep the gut quiet on race morning
Reduce GI risk the way the stand lists: smaller dose, ~180 min lead, with a high-carbohydrate meal, or enteric-coated capsules — and rehearse in training; responses vary within the same person
β-alanine co-supplementation may be additive (the stand; see REF-351, where the bicarbonate + β-alanine combination gave the largest pooled effect)
Not from this paper; the base's own practice: sodium citrate is sometimes used as a gentler alternative; the stand does not cover it

Limitations

GI side-effects are the practical constraint; the stand gives no incidence figure
Part of the effect is placebo-driven (the stand's own point 10)
The 30 s-12 min window means limited relevance to events beyond it; the stand makes no claim for longer efforts
The earlier-cited Hadzic 2019 and Grgic 2020 sources were not re-checked; their figures are not carried here

Audit note (2026-07-06)

DOI: 10.1186/s12970-021-00458-w | PMID: 34503527 [DOI CORRECTED 2026-07-09]
Level A → B+: the primary source Hadzic is not a Level A meta-analysis, but a review with heterogeneous results. [2026-09-27: the entry is now written from the DOI-bearing ISSN position stand, so the level returns to A — see Level line.]
How this entry was checked and changed
Why this level

regraded 2026-09-27 from B+: the DOI-bearing source is a governing-body position stand

Content correction 2026-09-27
Entry text described Hadzic 2019 / Grgic 2020 while the DOI line resolves to the ISSN position stand (Grgic 2021); text re-anchored on the ISSN abstract. "17 of 35 studies positive" (Hadzic) -> not checked; removed.
"ES ~0.17-0.30", "events 1-10 min", "split over 30-60 min", "3-8 min TTs", "5 g every 15-20 min at 90-120 min", "15-30% significant GI distress", "limited efficacy >15 min" -> none in the ISSN abstract; replaced with its figures (0.2-0.5 g/kg; 0.3 optimal; 60-180 min; 30 s-12 min; 3-7 day protocols at 0.4-0.5 g/kg/day).
Level B+ -> A (position stand). Sport "cycling, running, team-sport" -> the disciplines the stand names.
2026-09-28: added Journal from the Europe PMC record (PMID 34503527).