Sodium Bicarbonate Supplement: Benefits, Dosage, Risks, and Science

Sep 1, 2025

Can a pantry staple like baking soda really be a game-changing health supplement? Sometimes-if you pick the right use, dose it precisely, and respect the sodium. It can sharpen high-intensity exercise, tame occasional heartburn, and support certain kidney protocols under medical care. It won’t fix gut health, burn fat, or detox anything. If you want real benefits without the nasty side effects, you need a plan.

• TL;DR: It helps most in short, hard efforts (1-10 minutes), occasional heartburn, and specific kidney uses your clinician prescribes.
• Dose for sport: 0.2-0.3 g/kg body weight, 60-180 minutes pre‑event; split or “micro‑dose” to cut nausea and diarrhea.
• Each gram carries ~274 mg sodium. A typical sport dose can add 1,000-5,000 mg sodium-enough to spike blood pressure in some people.
• Avoid or get medical clearance if you have hypertension, heart, liver, or kidney disease, edema, are on lithium, or you’re pregnant.
• Use food‑grade powder or enteric‑coated capsules, never “industrial” grade. Not a daily health tonic.

What sodium bicarbonate does (and when it actually helps)

Sodium bicarbonate is a buffer. In plain English, it mops up acid. During very hard exercise, your muscles burn and performance fades partly because hydrogen ions build up. Bicarbonate in your blood can soak up some of that acid, letting you push a bit longer before your legs tie up. That’s why athletes reach for it.

The second common use is as an antacid. It neutralizes stomach acid quickly. A small dose can calm occasional heartburn. It’s also used medically to alkalinize urine and manage certain types of metabolic acidosis-those are clinical situations and not DIY territory.

What it won’t do: it doesn’t “detox” your body, it won’t raise resting pH to make you “alkaline,” and it’s not a daily longevity hack. Your lungs and kidneys keep your pH on a tight leash already.

How strong is the athletic evidence? Multiple randomized trials show performance gains for high‑intensity efforts lasting about 1 to 10 minutes: 400-1500 m running, 1-4 km cycling time trials, repeated sprints, and CrossFit‑style bouts. A 2018 review in the International Journal of Sport Nutrition and Exercise Metabolism reported small‑to‑moderate improvements, especially when dosing and timing are dialed in. A 2021 meta‑analysis in Sports Medicine echoed this-benefits are clearest for short, severe efforts, not for easy endurance cruising.

“Acute sodium bicarbonate ingestion (≈0.2-0.3 g/kg) can enhance performance in high‑intensity exercise, though gastrointestinal side effects and individual responses vary.” - International Society of Sports Nutrition, Position Stand (2021)

What about health beyond sport? Clinically, sodium bicarbonate shows benefits in select kidney disease patients with metabolic acidosis. In a 2009 randomized trial in the Journal of the American Society of Nephrology, prescribed bicarbonate slowed kidney function decline. That’s promising-but it’s tightly supervised dosing, with labs. It’s not a self‑experiment.

For heartburn, it’s fast but short‑acting. If you need it more than occasionally, H2 blockers or proton pump inhibitors-used appropriately-tend to work better and don’t pack a sodium bomb.

How to use it safely: doses, timing, and forms

Before you think dose, think goal. Are you trying to shave seconds off a hard interval session? Calm twice‑a‑month heartburn? Support a condition your doctor is treating? Different goals, different playbooks.

sodium bicarbonate supplement

Sport performance (acute):

• Standard dose: 0.2-0.3 g/kg body weight. Most people land at 0.2-0.25 g/kg to balance benefits and gut comfort.
• Timing: 60-180 minutes before the effort. Peak blood alkalosis often hits ~60-90 minutes, but some folks feel better at 2-3 hours due to fewer GI issues.
• Split dosing: Divide the total into 3-4 smaller doses over 60-120 minutes. This cuts nausea and bloating.
• Micro‑dosing (for repeated events): ~0.1 g/kg taken 3-4 times in the 24 hours leading into the event can work similarly with less GI distress.
• Co‑ingestion: Take with a small, familiar carb‑rich snack. Avoid spicy/fatty foods near dosing.

Sport performance (chronic loading):

• Some protocols use ~0.1 g/kg, 2-3 times daily for 3-5 days before competition. This may raise blood bicarbonate while reducing gut fallout.
• Evidence is mixed compared to a single big hit, but it’s worth testing in training weeks-not on race day.

Heartburn (occasional):

• Common OTC dose: ½ teaspoon (about 2.3 g) dissolved in at least 120-240 mL water after meals or when symptoms hit.
• Never exceed label directions. Space doses by at least 2 hours. If you need it most days, talk to your clinician about other options.

Forms and what to buy:

• Food‑grade baking soda (sodium bicarbonate) from a grocery store is fine for mixing into water.
• Enteric‑coated capsules or “buffered” formulas can reduce burping and nausea by delaying release past the stomach.
• Avoid industrial or cleaning grades. You want food or pharmaceutical grade only.

Sodium math you must know:

• 1 g sodium bicarbonate = ~274 mg sodium.
• Canada and the U.S. both suggest keeping daily sodium below about 2,300 mg. Most adults already exceed that.
• A sport dose can blow past your daily sodium in one go. Plan the rest of your day’s salt around it.

How to test your personal response (sport):

1. Pick a repeatable session (e.g., 4 × 1,000 m on the track with 3 min rest, or 6 × 2‑min hard bike intervals).
2. In week 1, do it without bicarbonate. Record times, RPE (how hard it feels), gut comfort, and any cramping.
3. In week 2, try 0.2 g/kg split dose, 90 minutes before. Repeat the exact same session. Compare.
4. If GI upset hits, try 0.2 g/kg micro‑dosed (0.1 g/kg × 2 doses) or 0.15 g/kg single dose. Many perform just as well at lower or split doses.
5. Stick with what gives you a clear gain in time or power with tolerable gut impact.

Simple mix method:

• Dissolve the powder fully in cool water. Add a splash of citrus juice to improve taste if your stomach tolerates it.
• Chase with a small carb snack (banana, toast, rice cake) if you’re prone to queasiness.
• Avoid carbonated drinks and high‑fat meals around the dose.

Who should skip it, common pitfalls, and smart workarounds

Skip or get medical clearance if any of these fit:

• High blood pressure, heart failure, kidney disease, liver cirrhosis, or swelling in legs/ankles.
• Pregnancy or breastfeeding.
• On sodium‑sensitive medications: lithium (bicarbonate can change lithium levels), certain antibiotics, or medicines where urine pH matters.
• History of stomach ulcers or severe reflux.

Major pitfalls to avoid:

• Big, fast dose on race day. That’s how you end up sprinting to the porta‑potty.
• Layering more sodium on a salty day. If you’re already salting food or using electrolyte drinks, your total sodium can get extreme fast.
• Daily “alkalizing” use. That’s not a thing you need, and you could destabilize potassium and acid‑base balance.
• Using it to self‑treat kidney issues. Clinical dosing is individualized, monitored with blood and urine tests.

How to reduce GI issues:

• Split the dose. Four mini‑servings beat one big slug.
• Use enteric‑coated capsules if you’re very sensitive.
• Time it 2-3 hours before hard work if you tend to bloat.
• Stick with familiar bland carbs around dosing, not new gels or spicy foods.

Alternatives and when to choose them:

• Beta‑alanine: Builds carnosine inside muscle to buffer acid from within. It’s a daily supplement (not pre‑workout) and helps efforts in the same 1-4 minute range but takes 4-8 weeks to work. Good if your stomach hates bicarbonate.
• Sodium citrate: Another buffer with similar performance effects; some people tolerate it better, others worse. Dose and sodium concerns are similar.
• For heartburn: On‑label antacids like calcium carbonate, or H2 blockers (famotidine) if symptoms are frequent. They don’t carry the same sodium wallop.

Real‑world nuance (and a Toronto‑specific note): most adults here already overshoot sodium targets. Health Canada recommends keeping sodium below ~2,300 mg per day; many Canadians land north of that. If you add a sport dose of bicarbonate, you’re stacking several days’ worth of sodium at once. Plan your meals accordingly or skip the supplement if blood pressure is touchy.

Quick tools: examples, checklist, and mini‑FAQ

Use these snapshots to match your situation.

Examples

• Track cyclist, 70 kg, 1 km time trial: Try 0.2 g/kg (14 g total) split into 4 doses over 90 minutes, last sip 60 minutes pre‑start. Pair with a low‑fat carb snack. Test in training twice before race day. If gut is iffy, switch to 0.15 g/kg or enteric capsules.
• CrossFit athlete, 82 kg, 8‑minute metcon: Start at 0.2 g/kg (16.4 g) two hours before event, split into 3 doses with applesauce or rice cake. If you feel sloshy, try micro‑dosing 0.1 g/kg the night before, then 0.1 g/kg 2 hours pre‑event.
• Weekend runner with occasional heartburn: Dissolve ½ teaspoon in water after a spicy dinner. If you need it more than once or twice a week, book a chat about H2 blockers and lifestyle tweaks.

One‑page checklist

• Goal fits? (short, hard efforts; occasional heartburn; clinician‑directed medical use)
• Contraindications checked? (BP, heart, kidney, liver, pregnancy, meds)
• Dose chosen? (0.2-0.25 g/kg for sport; ½ tsp for occasional heartburn)
• Timing set? (60-180 minutes pre‑event; split dosing to cut GI issues)
• Sodium planned? (1 g bicarb = ~274 mg sodium; adjust the day’s salt)
• Trial in training done? (never first use on race day)
• Backup plan? (lower dose, micro‑dosing, enteric capsules, or beta‑alanine)

Mini‑FAQ

• Does it help long endurance events? Not really for steady pacing. It’s more for short, intense efforts or hard surges. Some ultra athletes use it for late‑race surges, but testing is key.
• Can I use it with caffeine? Yes. They work through different mechanisms. Start with your usual caffeine plan; add bicarbonate only after a few successful tests.
• Will it cramp my stomach? It can. Nausea, bloating, diarrhea, and belching are common at higher doses. Splitting doses helps a lot.
• Is baking powder the same? No. Baking powder includes acids and starch. You want pure sodium bicarbonate (baking soda).
• Will it raise my blood pressure? It can. The sodium load is big. If your BP is borderline, skip it or get medical clearance and monitor closely.
• Can I take it daily for gut health? No good reason and several risks. Don’t.
• Is it banned in sport? No. It’s permitted. Still, follow anti‑doping rules for anything else in your stack.

What the research actually says (brief receipts)

• Performance: Multiple trials and meta‑analyses (e.g., 2018 International Journal of Sport Nutrition and Exercise Metabolism; 2021 Sports Medicine) show small‑to‑moderate gains in high‑intensity work when dosing is right.
• Side effects: Reviews highlight GI distress as the main limiter; splitting doses and enteric coatings improve tolerance (2018 review, Int J Sport Nutr Exerc Metab).
• Kidney disease: In adults with metabolic acidosis, prescribed sodium bicarbonate slowed eGFR decline (de Brito‑Ashurst et al., 2009, JASN). Not for self‑treatment.
• Heartburn: Recognized as an OTC antacid in regulatory monographs. Works fast, short duration, high sodium.
• Sodium guidance: Health Canada and the National Academies recommend keeping daily sodium under ~2,300 mg for most adults.

Fast decision guide

• If your key sessions are all‑out 1-10 minutes: Consider it. Test 0.2 g/kg split dosing.
• If you’re a steady marathoner with no surges: Skip it; focus on carbs, fluids, pacing, caffeine.
• If you get heartburn twice a month: Keep baking soda as a backup. If frequent, go see your clinician.
• If you have high blood pressure or kidney issues: Don’t self‑supplement.

Risks you can’t ignore

• Electrolyte shifts: Overdoing alkalinizing agents can lower potassium.
• Metabolic alkalosis: Rare but possible with heavy dosing, especially if vomiting or on diuretics.
• Drug interactions: Lithium levels can change with sodium; urine alkalinization alters clearance of some drugs (e.g., salicylates).

How to talk about it with your clinician

• Share your exact plan: g/kg dose, timing, frequency, and why (race vs. daily use).
• Bring your BP readings and any meds you take.
• Ask whether your labs (kidney function, electrolytes) warrant caution.

My take after testing it with athletes: it’s a scalpel, not a hammer. For the right workout or race, it’s a clean, legal edge-if your stomach cooperates and your sodium budget can absorb it. For day‑to‑day health? You’ve got better tools.

Next steps

• Endurance athlete with short intense efforts: Plan two test weeks. Start with 0.2 g/kg split, 90 minutes pre‑session. Log times, RPE, gut. Adjust to 0.15-0.25 g/kg or micro‑dose if needed.
• Strength/power athlete with lactic finisher: Use micro‑dosing (0.1 g/kg × 2) within 24 hours of the session. Pick low‑fat carbs around dosing.
• Person with occasional heartburn: Use ½ tsp dissolved in water sparingly. If symptoms persist, book a medical review.
• Anyone with BP, kidney, heart, or on lithium/diuretics: Skip self‑experiments and ask your clinician first.

Troubleshooting

• Nausea/diarrhea: Split dose into 3-4 servings, or switch to enteric‑coated capsules. Consider 0.15-0.2 g/kg instead of 0.3 g/kg.
• No performance gain: You may be a non‑responder at that dose/timing. Try micro‑dosing, different timing (2-3 hours pre), or beta‑alanine for a steadier buffering approach.
• BP spike or ankle swelling: Stop and talk to your clinician. The sodium load may be too high for you.
• Burping/bloating: Ensure the powder is fully dissolved; use still water; avoid carbonated mixers.

Bottom line: keep it targeted. When the job fits-hard, short efforts; quick heartburn relief; prescriber‑led protocols-it can pull its weight. If the job is general health, look elsewhere.