The GI Problem: Why Most Athletes Quit Bicarb (And Why They Don't Have To)
There's a version of this story that every serious endurance athlete knows. You read about sodium bicarbonate — the science is compelling, the performance gains are real. You try it before training. And then you spend the next two hours regretting it.
This is the single biggest barrier to bicarbonate supplementation: not whether it works (it does), but whether you can tolerate it well enough to actually use it on race day. And for most athletes using raw baking soda or poorly formulated products, the answer has historically been no.
Here's a clear-eyed explanation of why the GI problem exists — and what it means that it is now solvable.
What Actually Happens in Your Gut
When you consume raw sodium bicarbonate, it arrives in your stomach as a highly alkaline compound entering an acidic environment (stomach pH is typically 1.5–3.5). The immediate chemical reaction is straightforward:
NaHCO₃ + HCl → NaCl + H₂O + CO₂
That CO₂ is the gas responsible for the bloating, belching, and cramping that athletes experience within 30–60 minutes of consumption. But the gas is only part of the problem.
Sodium bicarbonate is also highly osmotically active. When a large dose of it enters the small intestine — which it does rapidly when it isn't encapsulated — it draws water from the surrounding tissues into the intestinal lumen through osmosis. The result is the rapid onset of osmotic diarrhoea: loose, urgent, and timed perfectly to coincide with your warm-up.
The Dose-Response Problem
The effective dose of sodium bicarbonate for performance is 0.2–0.3g per kilogram of body weight. For a 75kg athlete, that's 15–22.5g — roughly one to one-and-a-half tablespoons of raw powder.
That is a lot of a strongly alkaline, osmotically active substance to introduce to your GI tract in a short period. The severity of symptoms scales with dose, individual gut sensitivity, and hydration status. Some athletes experience mild effects; for others, even modest doses cause significant distress.
The effective dose of bicarb is not trivially small. For a 75kg athlete, it's 15–22g — and in raw form, that amount is almost guaranteed to cause some degree of GI disruption.
Why Athletes Have Tried to Work Around It — And Why Those Workarounds Mostly Fail
Over the years, athletes and coaches have developed various strategies to mitigate the GI effects of raw bicarbonate:
1. Splitting the dose across multiple smaller servings — This reduces the acute osmotic load but extends the time window over which you're managing discomfort, and the timing becomes difficult to manage pre-race.
2. Taking it with food — A meal slows gastric emptying, which can reduce the intensity of symptoms, but also delays absorption unpredictably.
3. Using sodium bicarbonate capsules (generic pharmacy capsules) — Better than raw powder, but generic capsules are not designed to survive the stomach intact. They dissolve in the acidic gastric environment just as raw powder does.
4. Chronic loading over multiple days — Some research supports spreading doses over 3–7 days at lower daily amounts. This can reduce acute GI distress but requires careful compliance and planning, and the cumulative alkaline load still challenges many athletes' guts.
None of these workarounds fully solve the problem because they don't address the root cause: the bicarbonate dissolving in the wrong part of the digestive tract.
The Delivery Problem — And Why It Was Always Solvable
The GI side effects of sodium bicarbonate are not an intrinsic property of the compound. They are a consequence of how and where it dissolves. This is a pharmaceutical delivery problem, and pharmaceutical science has a well-established solution: enteric coating.
Enteric-coated or encapsulated formulations are designed to resist dissolution in the acidic stomach environment and instead release their contents in the neutral-to-alkaline environment of the small intestine. This is the same principle used in delayed-release medications for conditions like GERD, where you want the drug to bypass the stomach entirely.
Applied to sodium bicarbonate, this approach means the bicarbonate passes through the stomach intact — no CO₂ reaction, no osmotic load — and dissolves in the small intestine, where it is absorbed directly into the bloodstream to elevate plasma bicarbonate levels.
The result is the same buffering benefit, delivered via the same physiological mechanism, but without the GI consequences that made raw bicarbonate impractical for race-day use.
The GI problem with bicarb has never been about the compound itself. It's always been a delivery problem — and delivery problems have known solutions.
What This Means for You as an Athlete
If you've avoided bicarbonate supplementation because of GI concerns — or tried it once and written it off — the equation has changed. An encapsulated delivery system designed for gut safety removes the primary barrier that has historically made bicarb an unreliable race-day tool.
The practical implication: you can now approach bicarbonate loading as a repeatable, predictable part of your race preparation rather than a high-risk experiment with an uncertain outcome.
• The performance benefit remains the same: 1–3% improvement in high-intensity performance, backed by 40+ years of research
• The dose remains the same: 0.2–0.3g/kg of body weight, 60–150 minutes pre-event
• The difference is what happens between ingestion and absorption
BiCarb Plus was formulated specifically to make this possible: a product where the science and the tolerability are no longer in conflict.
