If you’ve been following elite running at all the past year or two, you know there’s a controversy over a “new” product called bicarb.
Along with super shoes, bicarb has been attributed to the recent assault on world records.
But, does it really work? Or is this just another “overhyped” product beetroot juice was a few years ago?
Well, that’s what we’re going to explore in this article. We’ll look at the research and…
- Breakdown what exactly bicarb is and what it’s theorized to do
- Look at the early research and why it’s only now becoming popular
- Dig deep on the more recent scientific literature to see if it has any merit
- And finally provide some practical strategies should you want to try it.
What exactly is bicarb?
“Bicarb” is a common shorthand for bicarbonate of soda, which is also most commonly known as baking soda or sodium bicarbonate (NaHCO3).
Yes, this is the same white powder you usually associate with as a leavening agent in baking.
Interestingly, while it’s only recently gaining popularity, bicarb loading has a long history in sports science generally and running in particular.
That’s because sodium bicarbonate is a salt that breaks down to form sodium and bicarbonate in water. This makes a solution alkaline, meaning it’s able to neutralize acid.
Thus, taking a bicarb supplement was originally thought up as an almost comically simple solution to the problem of fatigue: if lactic acid causes fatigue, take bicarb to neutralize the acid!
While we now know that the problem of fatigue in running is a lot more complex than “lactic acid” the surprising thing about bicarb supplementation is that it actually worked—on paper at least.
The early days of bicarb loading
A wave of positive results from studies in the 1980s and 1990s showed that taking a high dose of bicarb just before a hard anaerobic effort (like running a mile all-out) improved performance in sports like running, swimming, and cycling.
But after this initial wave of interest, bicarb became something of a poster child for a supplement that worked in the lab, but whose real-world side effects were so irksome that it just wasn’t worth it.
The trouble with bicarbonate is twofold:
- First, it is a strongly alkaline substance, so just like baking soda reacting with vinegar, bicarbonate reacts with the acids in your stomach, changing the chemical environment of your digestive tract.
- Second, the traditional dose of bicarb was very large—sometimes upwards of 25 grams—which amplified the gut-disturbing effects [1].
The result is what physiology researchers delicately call “gastrointestinal disturbances”: nausea, flatulence, vomiting, bloating, and diarrhea, all occurring right before you’re about to start your big race.
A professor I had in graduate school told stories of some of his early work on bicarb loading in swimmers, who would leap out of the pool after their time trial to make a mad dash for the bathroom.
The Maurten Bicarb System
On account of these side effects, bicarb was not widely used outside of sports science research until 2023, when sports nutrition company Maurten launched its “bicarb system,” a new take on bicarb loading.
Maurten, already known for its sports drinks and energy gels that claimed to use a hydrogel compound to speed up carbohydrate absorption, applied the same technology to bicarbonate.
The launch of this new system, plus flashy press releases and media spotlights claiming up to 80% of track athletes at the Paris Olympics would be using it, created a huge amount of buzz around bicarb in general, and Maurten’s system in particular.
The Maurten bicarb system doesn’t claim to enhance the effectiveness of bicarbonate itself. All it does (according to the company) is make two tweaks to reduce the risk of gastrointestinal problems.
First, instead of a raw powder, the bicarbonate is pressed into miniature tablets, resulting in less surface area to react with stomach acid.
Second, the Maurten system uses a hydrogel that congeals into a thick, gel-like consistency on contact with acidic liquids. The hydrogel aims to further slow down the reaction between bicarbonate and stomach acid, delaying the release of bicarb until it gets into the small intestine.
Does bicarb really work? What the science says
When it comes to bicarbonate loading in general, the science is fairly clear: for events lasting about 45 seconds to eight minutes in duration, you can get a performance benefit of a few percentage points—roughly on par with the effects you’d see from caffeine.
That was the conclusion of a 2017 meta-analysis that pooled data from 25 different studies on bicarbonate loading [2], which found very similar performance benefits for bicarb and caffeine.
A later review from 2021 came to a similar conclusion: for short to middle-distance events, where fatigue is dominated by “peripheral fatigue” in the muscles caused by anaerobic energy production, bicarbonate loading exerts a small but significant effect on performance [3].
As for Maurten’s bicarb system specifically, there are, understandably, fewer reliable studies.
In total, three papers have tested the Maurten bicarb system, though all of them are in male cyclists and two are actually repeat studies on the same athletes.
In terms of efficacy, the Maurten system seems to work as well as traditional bicarbonate supplements, according to a 2024 study on 14 cyclists who completed a 40 km time trial [4].
Compared with a placebo, the cyclists covered the 40 km distance 1.5% faster, in line with research on traditional bicarb loading.
This study found no significant difference in gastrointestinal symptoms between the placebo and the bicarb.
But especially in a small study, “absence of evidence” is not the same thing as “evidence of absence”—the study might’ve just been too small to see an effect on stomach problems, and this paper did not directly compare traditional bicarb with Maurten’s system.
One study that did do a direct comparison was a 2024 paper on 12 cyclists who completed a progressive exercise test either after taking Maurten bicarb or a traditional bicarb supplement [5].
This paper found significantly lower gastrointestinal problems in the Maurten group, but similar blood levels of bicarbonate, suggesting the bicarb was indeed making its way into the bloodstream.
The same research group separately published data from a subset of 10 of these 12 cyclists who returned for two sets of 2 x 4 km time trials that they completed after taking either Maurten bicarb or a sodium chloride (i.e. table salt) supplement [6].
While the cyclists did improve their performance with the bicarb supplement, this experiment also isn’t quite what we want: a head-to-head three-way comparison of Maurten, traditional bicarb, and placebo, that tracks both performance and gastrointestinal complaints.
Practical strategies for using bicarb for runners
So, does Maurten’s bicarb system live up to the hype?
The truth is we don’t have enough data. There are zero studies on Maurten’s bicarb system in runners, and zero studies on women in any sport.
- Bicarb loading as a general strategy does have solid evidence supporting its efficacy in events lasting from 45 seconds to eight minutes
- You can probably argue that the benefits would carry over to championship-style sit-and-kick races lasting up to 15 or even 30 minutes
- But for longer races (like the marathon), any benefit is far less clear.
- Longer events also leave you much more vulnerable to the well-known gastrointestinal side effects that come along with traditional bicarbonate loading.
If you are competing in short-distance events and want to try the Maurten system, the usual golden rule applies: try it out in a workout first.
The usual research-backed protocols involve taking 300 mg of bicarb (0.3 grams) per kilogram of body weight, within one to two hours of your workout or race.
In all likelihood, runners vary in their degree of susceptibility to gastrointestinal problems, so test out your body’s reaction first before taking bicarb on race day.
