Quick Answer
Yes, fancy bicarb mixes like Maurten Bicarb System or Blanks Bicarb cause fewer GI issues than raw baking soda. The reason is simple: they use a slow-release or buffered formula that reduces the sudden pH shift in your stomach. Raw baking soda (sodium bicarbonate) dissolved in water releases CO2 gas rapidly, leading to bloating, cramping, and diarrhea. Commercial products add ingredients like sodium citrate, citric acid, or a hydrogel matrix to control the release. You can also reduce stomach pain by splitting the dose, taking it with a big meal, or using a lower total amount (0.2–0.3 g/kg instead of 0.5 g/kg).
Why This Happens
Sodium bicarbonate works as an ergogenic aid because it buffers lactic acid buildup in your muscles during high-intensity efforts like 800m to 5k races. The problem is that your stomach is not designed to handle a sudden flood of alkaline bicarbonate. When you mix raw baking soda with water, it fizzes violently — that’s CO2 being released inside your stomach. That gas causes distension, pressure, and often triggers a laxative effect. Additionally, the high sodium load (about 1.2 grams of sodium per teaspoon) draws water into your gut, causing cramping and diarrhea. Advanced runners often try 0.5 g/kg (about 5 teaspoons for a 70 kg runner) and end up regretting it.
Step-by-Step Method to Use Bicarb Without Pain
- Choose a specialized product. Look for “bicarb system” or “buffered bicarbonate” from Maurten, Blanks, or similar. These combine bicarbonate with a hydrogel or acid regulator to slow gastric emptying and reduce gas production.
- Calculate your dose conservatively. Start at 0.2 g/kg of body weight. For a 70 kg runner, that’s 14 g (about 2.8 teaspoons). Never exceed 0.5 g/kg in one go.
- Time it right. Take the dose 60–90 minutes before your race or hard workout. Some products require a staged loading (e.g., Maurten’s protocol: four 250 mL doses over 2 hours). Follow the product instructions precisely.
- Mix with a sports drink or juice. The sugar and acidity can help mask the taste and reduce direct stomach irritation. Avoid plain water; carbonated water makes things worse.
- Test during training. Never try a new bicarb protocol on race day. Simulate the exact timing and dosage during a hard workout to see how your gut reacts.
- Consider split dosing. Instead of one large drink, take half the dose 90 minutes before and the other half 45 minutes before. This spreads the gastric load.
Common Mistakes
- Using raw baking soda at full racing dose (0.5 g/kg). That almost always causes GI upset. Even elites rarely use that much. Cut it to 0.2–0.3 g/kg.
- Taking bicarbonate on an empty stomach. Without food to buffer the pH jump, your stomach empties faster and you get hit with gas and nausea. Eat a small, low-fat meal (like a banana and a slice of toast) 30–60 minutes before.
- Mixing with only water and drinking quickly. Sipping slowly over 10–15 minutes reduces the CO2 rush. Chugging leads to burping, bloating, and urgent bathroom breaks.
- Assuming all bicarb products are the same. Raw baking soda is not equivalent to Maurten Bicarb. The delivery system matters more than the dose.
- Skipping a practice run. Bicarb tolerance is individual. Someone who can handle 0.3 g/kg may have issues at 0.4 g/kg. Test incrementally.
- Using bicarbonate for events longer than 60 minutes. The buffering effect is most useful for efforts where lactate builds quickly — 800m to 10k. For marathons, the GI risk outweighs the benefit.
Checklist or Decision Table: Bicarb Options Compared
| Product | Dose per serving | Total sodium (mg) | GI issues | Cost per dose | Notes |
|---|---|---|---|---|---|
| Raw baking soda (bulk) | 1 tsp ≈ 4.8 g | 1,200 mg | High | ~$0.05 | Chunky, terrible taste, gas guaranteed |
| Maurten Bicarb System (4-drink box) | 4 x 250 mL = 16 g total | ~1,600 mg | Low | ~$8.00 | Hydrogel matrix, staged protocol |
| Blanks Bicarb (single packet) | 8 g (mix with 200 mL) | ~1,000 mg | Low–Moderate | ~$2.50 | Buffered with citrate, good flavor |
| Osmo Bicarb Load | 12.5 g per pouch | ~1,500 mg | Moderate | ~$3.00 | Contains electrolytes, can cause mild bloating |
| DIY buffered (bicarb + lemon juice) | 0.3 g/kg + juice | Varies | Moderate | ~$0.20 | Reactivity reduces gas slightly, but still risky |
Decision rule: If you are competing at a high level (sub-elite or elite) and want reliable performance without mid-race GI distress, choose Maurten or Blanks. If you are on a budget and only doing occasional intense efforts, try a half dose of raw bicarb (0.2 g/kg) mixed with apple juice. Never use raw bicarb for a race without testing first.
When This Advice Does Not Apply
- If you have a history of stomach ulcers, GERD, or IBS. Bicarbonate supplementation can aggravate these conditions. Consult a doctor first.
- During a marathon or longer event. The buffering benefit is negligible past 60–90 minutes, but the GI risk remains. Don’t use bicarb for a marathon.
- When you are dehydrated. Bicarb draws water into the gut and can worsen dehydration. Make sure you are well-hydrated before dosing.
- If you are on a low-sodium diet for medical reasons. The sodium load is high. Check with your physician.
- If you are a beginner runner still building base mileage. Bicarb is an advanced tool for already-fit athletes. Focus on nutrition, hydration, and training consistency first.
Realistic Example
Runner profile: Alex, 72 kg, male, 5k PR 16:30, aiming to break 16:00. He read about sodium bicarbonate on Reddit and tried 5 teaspoons of Arm & Hammer in water an hour before a time trial. Within 20 minutes he had bloating, then urgent diarrhea, and ran 16:45.
Solution: Alex switches to the Maurten Bicarb System. He follows the staged protocol: four 250 mL drinks starting 2 hours before the race, but he drops the last dose to see how his gut handles it. He tests this during a threshold workout one week before the race. No GI issues. On race day, he completes the full four-dose protocol, runs 15:58, and reports no stomach pain.
Key takeaway: The specific product and protocol made the difference, not the bicarbonate itself.
Final Takeaway
Sodium bicarbonate can boost your performance in events from 800m to 10k, but only if you avoid the stomach pain that ruins the effort. The best strategy is to use a commercial bicarb product designed for controlled release, start with a lower dose (0.2–0.3 g/kg), take it 60–90 minutes before, and always test it in training first. If you stick with raw baking soda, cut the dose in half and mix it with a sugary drink. Never gamble your race on an untried gut load.
FAQs
Can I use baking soda from the grocery store for running?
Yes, but with major caveats. Grocery store baking soda is pure sodium bicarbonate and works the same chemically. However, the risk of GI upset is much higher because it releases CO2 rapidly. If you must use it, take only 0.2 g/kg (about 3 teaspoons for a 70 kg runner), mix with 300 mL of fruit juice, and sip over 10 minutes. Even then, test during a training session first. Don’t expect the same comfort as a specialized product.
How much sodium bicarbonate should I take for a 5k?
The effective range is 0.2–0.3 g per kilogram of body weight. For a 70 kg runner, that’s 14 to 21 grams. Do not exceed 0.5 g/kg. Split the dose into two servings 30–45 minutes apart to reduce stomach distress. Also, time your last dose to be 60–90 minutes before the start so that blood bicarbonate peaks during the race.
Do Maurten Bicarb or Blanks actually work better than raw powder?
Yes, they work better for most runners because they reduce GI side effects while delivering the same amount of bicarbonate. Maurten uses a hydrogel that encapsulates the bicarbonate and delays its release. Blanks adds sodium citrate and flavoring to buffer the pH shift. Both have been tested in controlled studies and by elite athletes. Raw powder is cheaper but much harder on the stomach.
What if I get diarrhea after taking bicarb?
Diarrhea is a common sign of too much bicarbonate or taking it too quickly. Stop the protocol immediately. For future attempts, cut the dose by 30–50%, ensure you are well-hydrated, and take it with a small meal. If the problem persists, consider switching to a buffered product like Blanks or reduce the dose further. Persistent GI issues may mean bicarbonate is not suitable for you.
Should I take bicarbonate with or without food?
Take it with food — a light meal like a banana or a slice of toast. Food slows gastric emptying and buffers the bicarbonate, reducing gas and bloating. Avoid high-fat meals because they delay emptying too much and may cause nausea. Do not take it on an empty stomach; that’s a direct path to cramping and diarrhea.
Can I combine bicarbonate with other supplements like beta-alanine?
Yes, they work synergistically. Beta-alanine increases intramuscular carnosine levels, which buffers hydrogen ions inside the muscle, while bicarbonate works in the blood and extracellular space. Combining them can improve performance further, but be cautious with GI effects — the total osmotic load increases. Start with lower doses of each and test separately. No evidence suggests dangerous interactions.