Sodium bicarbonate
Meta-analyses find about 0.3 g per kg of sodium bicarbonate improves short high-intensity efforts, by about 1.7% in a 1-minute sprint, and muscular endurance by SMD 0.37. Newer reviews found little or no change in running or 200 m swims. Maximal strength did not change. Gastrointestinal distress is common: 10 of 11 people had diarrhea in one trial.
Add to Bio HackChecked 2026-11-09
- Status
- Food ingredient and over-the-counter antacid in the US; also sold as a sports supplement.
- Also called
- baking soda, bicarb, NaHCO3, soda loading, bicarbonate loading, Maurten Bicarb, enteric-coated bicarbonate
- Taken for
- high-intensity performance, sprint endurance, buffering lactic acid, rowing, swimming, combat sports, more reps
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help3
- ModerateShown to raise power about 1.7% in a 1-minute sprint in athletes, with gains in efforts of 30 seconds to 12 minutes, smaller in longer tests.
- ModerateShown to improve high-intensity intermittent performance slightly in team-sport athletes. Repeated sprints and endurance showed no clear effect on their own.
- ModerateShown to improve muscular endurance, in both small and large muscle groups, in healthy adults.
Reported risks4
- StrongShown to raise stomach upset. At 0.3 g per kg, 10 of 11 athletes had diarrhea, and symptoms likely rise with dose.
- LimitedOne small trial found 0.3 g per kg raised diastolic pressure about 3 mmHg and heart rate about 10 beats per minute. This dose exceeds the sodium upper limit.
- LimitedCase reports: 192 baking soda misuse cases over 12 years in California, mostly antacid use, with 12 admitted for electrolyte imbalance or alkalosis.
- LimitedCase reports: very large amounts led to severe alkalosis, and massive single doses often to stomach rupture with high mortality, far above sports doses.
What people take it for, and what was found
Shown to help3
High-intensity efforts of about 30 seconds to 12 minutes
Shown to raise power about 1.7% in a 1-minute sprint in athletes, with gains in efforts of 30 seconds to 12 minutes, smaller in longer tests.
The numbers and sources
- Effect
- Across 38 studies and 137 estimates, about 0.3 g per kg gave a 1.7% (90% CL ± 2.0%) mean power improvement in a single 1-minute sprint by blinded male athletes. Each extra 1 mmol per kg raised the effect by 0.5%, five extra sprint bouts added 0.6%, and each 10-fold increase in test duration reduced it by 0.6% [1]. The ISSN position stand reports improvements in high-intensity cycling, running, swimming, rowing and combat sports lasting 30 seconds to 12 minutes [2].
- Population
- Mostly male athletes and non-athletes [1].
- Sources
- [1], [2]
- Caveats
- The 90% confidence limits are wide relative to the effect [1]. Reference [2] is an ISSN position stand, a narrative consensus. Newer meta-analyses of single sports found smaller or no effects in running and 200 m swimming (see below) [3][4].
Team-sport intermittent efforts
Shown to improve high-intensity intermittent performance slightly in team-sport athletes. Repeated sprints and endurance showed no clear effect on their own.
The numbers and sources
- Effect
- Across 20 studies with 53 effect sizes, bicarbonate improved high-intensity intermittent performance by Hedges' g 0.23 (95% CI 0.07 to 0.39, I² 37%). Repeated-sprint performance, mean power, intermittent endurance and work capacity showed no clear effect on their own. Sex, dose and formulation did not change the result [5].
- Population
- 241 team-sport athletes, acute or short-term doses [5].
- Sources
- [5]
- Caveats
- Certainty was low, and the prediction interval ran from -0.22 to 0.68 [5].
Muscular endurance (reps and time to fatigue)
Shown to improve muscular endurance, in both small and large muscle groups, in healthy adults.
The numbers and sources
- Effect
- In 13 studies, bicarbonate improved muscular endurance (SMD 0.37, 95% CI 0.15 to 0.59), in both small (SMD 0.31) and large (SMD 0.40) muscle groups [6].
- Population
- Healthy adults [6].
- Sources
- [6]
- Caveats
- One meta-analysis. Timing and the rise in blood bicarbonate did not predict the size of the effect [6].
Not shown to help4
Continuous running
Not shown to clearly improve continuous running overall. In trials of men only, running improved modestly.
The numbers and sources
- Effect
- Across 11 crossover trials of a single dose, typically 0.3 g per kg, the effect on running performance was SMD 0.18 (95% CI -0.01 to 0.36, I² 0%, moderate certainty) after adjusting for stomach-related dropouts and publication bias. In the 8 trials of men only, it was SMD 0.40 (95% CI 0.18 to 0.63) [3].
- Population
- 126 participants, 84% male, in tests of 1 to 30 minutes, median 4 minutes [3].
- Sources
- [3]
- Caveats
- Male sex and higher body mass were linked to larger effects in meta-regression [3].
200 m swimming
Not shown to improve 200 m swim times in swimmers, though it raised blood bicarbonate, lactate and pH.
The numbers and sources
- Effect
- Across RCTs in swimmers, bicarbonate raised blood bicarbonate (SMD 1.09), lactate (SMD 0.76) and pH (SMD 1.02), and did not change 200 m time (SMD 0.26, 95% CI -0.58 to 1.10) [4].
- Population
- Swimmers in RCTs against placebo [4].
- Sources
- [4]
- Caveats
- The authors note data limitations. The abstract does not give the number of trials [4].
Maximal strength
Not shown to change maximal strength in healthy adults, rested or fatigued.
Performance in women
Limited evidence: blood bicarbonate rose in women, but the exercise effect was uncertain. Only 20% of bicarbonate studies included women.
The numbers and sources
- Effect
- In 11 studies reporting women separately, blood bicarbonate rose by 7.4 mmol/L (95% CrI 4.2 to 10.4) and the pooled exercise effect size was 0.37 (95% CrI -0.06 to 0.92). Only 20% of 149 bicarbonate studies included women [7].
- Population
- Women [7].
- Sources
- [7]
- Caveats
- The credible interval crosses zero, though the authors describe the evidence as consistent with a small to medium effect [7].
Doses studied
The ISSN position stand reports doses of 0.2 to 0.5 g per kg, with 0.2 g per kg as the minimum single dose linked to improvement, 0.3 g per kg as the dose the stand identifies for performance effects, and 0.4 to 0.5 g per kg bringing more side effects without extra benefit. Single doses were taken 60 to 180 minutes before exercise. Multi-day protocols used 0.4 to 0.5 g per kg a day for 3 to 7 days, split into smaller doses [2]. One crossover study found taking 0.3 g per kg with a high-carbohydrate meal gave the highest blood bicarbonate (30.9 mmol/kg as reported) and the fewest GI symptoms [8].
Risks
Reported risks4
Gastrointestinal distress
Shown to raise stomach upset. At 0.3 g per kg, 10 of 11 athletes had diarrhea, and symptoms likely rise with dose.
The numbers and sources
- Effect
- In 11 endurance-trained adults given 0.3 g per kg, 10 (91%) had diarrhea, 64% had bloating and thirst, and 45% had nausea; distress rated 5.1 of 10 against 0.5 on placebo [9]. A review of 101 studies found common doses of 0.2 to 0.4 g per kg produced mild to severe GI symptoms that likely rise with dose. Spreading intake over hours, enteric-coated capsules and carbohydrate hydrogel delivery have been studied as ways to lower symptoms, but have not been compared directly [10]. GI symptoms peaked 90 minutes after a 0.3 g per kg solution [8]. In running trials, GI symptoms occurred in 29.5% on bicarbonate against 2.6% on placebo (OR 5.9, low certainty), and GI-related withdrawal in 8.7% against 1.6% (OR 2.9, moderate certainty) [3].
- Population
- Physically active and trained adults [8][9][10]. 126 runners in 11 crossover trials [3].
- Sources
- [8], [9], [10], [3]
- Caveats
- 26 of 101 studies did not test GI differences statistically [10].
Blood pressure, heart rate and sodium load
One small trial found 0.3 g per kg raised diastolic pressure about 3 mmHg and heart rate about 10 beats per minute. This dose exceeds the sodium upper limit.
The numbers and sources
- Effect
- In a double-blind crossover trial, 0.3 g per kg raised diastolic pressure by 3.3 mmHg and heart rate by 10.1 beats per minute, with no change in systolic pressure. The authors note bicarbonate is 27% sodium, so this dose exceeds the 2,300 mg daily sodium upper limit [9].
- Population
- 11 endurance-trained adults [9].
- Sources
- [9]
- Caveats
- One acute trial in athletes. People with high blood pressure were not studied. In chronic kidney disease, where bicarbonate is used to treat acidosis, 20 RCTs and 2 non-randomized trials (2,932 patients) found no significant difference from control in worsening edema (RR 1.26, 95% CI 0.94 to 1.68) or death or prolonged hospitalization (RR 1.05, 95% CI 0.84 to 1.32) [11].
Baking soda poisoning
Case reports: 192 baking soda misuse cases over 12 years in California, mostly antacid use, with 12 admitted for electrolyte imbalance or alkalosis.
The numbers and sources
- Effect
- The California Poison Control System recorded 192 symptomatic cases of baking soda misuse from 2000 to 2012. 55.2% had symptoms needing medical evaluation, and 12 were admitted with electrolyte imbalance, metabolic alkalosis or respiratory depression. Most cases involved antacid use (60.4%) or attempts to beat urine drug tests (11.5%) [12].
- Population
- Poison center case records, ages 2 months to 79 years [12].
- Sources
- [12]
- Caveats
- Case series, not sports use. No denominator of all users.
Severe alkalosis and stomach rupture from large amounts
Case reports: very large amounts led to severe alkalosis, and massive single doses often to stomach rupture with high mortality, far above sports doses.
The numbers and sources
- Effect
- A man in his 30s who took 60 g a day for 2 months, then 480 g at once, had blood pH 7.54, bicarbonate 54.5 mmol/L and sodium 162 mEq/L, and recovered with treatment. A review of 78 published cases found that acute massive ingestion was often complicated by stomach rupture and linked to high mortality, while chronic use mostly caused severe metabolic alkalosis and electrolyte disturbance [13].
- Population
- One case report and 78 published cases [13].
- Sources
- [13]
- Caveats
- Case reports, mostly far above sports doses. No denominator of all users [13].
Claims tested and not found
- That bicarbonate raises maximal strength. Pooled strength did not change across 11 studies [6].
- That more is better. The ISSN stand reports doses above 0.3 g per kg add side effects without extra performance [2].
- That bicarbonate speeds 200 m swim times. Pooled RCTs in swimmers found no change in 200 m time [4].
Sources
- Carr AJ, Hopkins WG, Gore CJ. Effects of acute alkalosis and acidosis on performance: a meta-analysis. Sports Medicine. 2011. https://doi.org/10.2165/11591440-000000000-00000
- Grgic J, Pedisic Z, Saunders B, et al. International Society of Sports Nutrition position stand: sodium bicarbonate and exercise performance. Journal of the International Society of Sports Nutrition. 2021. https://doi.org/10.1186/s12970-021-00458-w
- Miller LE, Bhattacharyya R, Katz SJ, et al. Negligible benefit of oral single-dose sodium bicarbonate on continuous running performance: systematic review with meta-analysis of randomized, double-blind, placebo-controlled trials. Journal of the International Society of Sports Nutrition. 2025. https://doi.org/10.1080/15502783.2025.2538606
- Huang D, Wang X, Takagi H, et al. Effects of sodium bicarbonate on 200 m time trial performance and physiological responses in swimmers: a systematic review and meta-analysis of randomized controlled trials. Research in Sports Medicine. 2025. https://doi.org/10.1080/15438627.2025.2456630
- Ge X, Sun H, Wu C, et al. Effects of acute or short-term oral sodium bicarbonate supplementation on high-intensity intermittent exercise performance and physiological responses in team-sport athletes: a systematic review and meta-analysis. Frontiers in Nutrition. 2026. https://doi.org/10.3389/fnut.2026.1936178
- Grgic J, Rodriguez RF, Garofolini A, et al. Effects of Sodium Bicarbonate Supplementation on Muscular Strength and Endurance: A Systematic Review and Meta-analysis. Sports Medicine. 2020. https://doi.org/10.1007/s40279-020-01275-y
- Saunders B, de Oliveira LF, Dolan E, et al. Sodium bicarbonate supplementation and the female athlete: A brief commentary with small scale systematic review and meta-analysis. European Journal of Sport Science. 2021. https://doi.org/10.1080/17461391.2021.1880649
- Carr AJ, Slater GJ, Gore CJ, et al. Effect of Sodium Bicarbonate on [HCO3-], pH, and Gastrointestinal Symptoms. International Journal of Sport Nutrition and Exercise Metabolism. 2011. https://doi.org/10.1123/ijsnem.21.3.189
- Kahle LE, Kelly PV, Eliot KA, et al. Acute sodium bicarbonate loading has negligible effects on resting and exercise blood pressure but causes gastrointestinal distress. Nutrition Research. 2013. https://doi.org/10.1016/j.nutres.2013.04.009
- Winter IP, Sarac P, Wilson PB. Gastrointestinal Symptoms Associated With Sodium Bicarbonate Supplementation Protocols: A Systematic Review. European Journal of Sport Science. 2026. https://doi.org/10.1002/ejsc.70225
- Siddiqui AH, Batool F, Khan S, et al. Safety and efficacy of sodium bicarbonate for treating metabolic acidosis in chronic kidney disease: A systematic review and meta-analysis. World Journal of Nephrology. 2025. https://doi.org/10.5527/wjn.v14.i1.101078
- Al-Abri SA, Kearney T. Baking soda misuse as a home remedy: case experience of the California Poison Control System. Journal of Clinical Pharmacy and Therapeutics. 2013. https://doi.org/10.1111/jcpt.12113
- Inokuchi R, Maeda A, Komaru Y, et al. Severe metabolic alkalosis and hypernatremia induced by excessive sodium bicarbonate intake: A case report and literature review. The American Journal of Emergency Medicine. 2026. https://doi.org/10.1016/j.ajem.2026.01.014