The Pill That Over Half the Distance Medallists Used at the 2023 Worlds
What's the deal with sodium bicarbonate?
By Jonathan GaultWhat if there was a pill, new to the market this year, that was used by more than half of the distance medalists at the 2023 World Athletics Championships? A supplement so in-demand that there was a reported black market for it in Budapest, runners buying from other runners who did not advance past the preliminary round — even though the main ingredient can be found in any kitchen?
How did this pill become so popular? Well, there are rumors that Jakob Ingebrigtsen has been taking it for years — rumors that Ingebrigtsen’s camp and the manufacturers of the pill will neither confirm nor deny.
So about this pill…does it work? Does it actually boost athletic performance? Ask a sports scientist, someone who’s studied it for more than a decade, and they’ll tell you yes.
“There’s probably four or five legal, natural supplements, if you will, that seem to have withstood the test of time in terms of the research literature and [this pill] is one of those,” says Jason Siegler, Director of Human Performance in the College of Health Solutions at Arizona State University.
But there’s a drawback to this pill. It could…well, let’s allow Luis Grijalva, who used it before finishing 4th in the World Championship 5,000m final in Budapest, to explain.
“I heard stories if you do it wrong, you chew it, you kind of shit your brains out,” Grijalva says. “And I was a little bit scared.”
The research supports that, too.
“[Gastrointestinal distress] has by far and away been the biggest hurdle for this supplement,” Siegler says.
Okay, enough with the faux intrigue. If you’ve read the subtitle of this article, you know the pill we are talking about is sodium bicarbonate. Specifically, the Maurten Bicarb System, which has been available to the public since February and which has been used by some of the top teams in endurance sports: cycling juggernaut Team Jumbo-Visma and, in running, the On Athletics Club and NN Running Team. (Maurten has sponsorship or partnership agreements with all three).
Some of the planet’s fastest runners have used the Maurten Bicarb System in 2023, including 10,000m world champion Joshua Cheptegei, 800m silver medalist Keely Hodgkinson, and 800m silver medalist Emmanuel Wanyonyi. Faith Kipyegon used it before winning the gold medal in the 1500m final in Budapest — but did not use it before her win in the 5,000m final or before any of her world records in the 1500m, mile, and 5,000m.
Herman Reuterswärd, Maurten’s head of communications, declined to share a full client list with LetsRun but claims two-thirds of all medalists from the 800 through 10,000 meters (excluding the steeplechase) used the product at the 2023 Worlds.
After years of trial and error, Maurten believes it has solved the GI issue, but those who have used their product have reported other side effects. Neil Gourley used sodium bicarbonate before almost every race in 2023, and while he had a great season — British champion, personal bests in the 1500 and mile — his head ached after races in a way it never had before. When Joe Klecker tried it at The TEN in March, he felt nauseous and light-headed — but still ran a personal best of 27:07.57. In an episode of the Coffee Club podcast, Klecker’s OAC teammate George Beamish, who finished 5th at Worlds in the steeplechase and used the product in a few races this year, said he felt delusional, dehydrated, and spent after using it before a workout this summer.
“It was the worst I’d felt in a workout [all] year, easily,” Beamish said.
Not every athlete who has used the Maurten Bicarb System has felt side effects. But the sport as a whole is still figuring out what to do about sodium bicarbonate.
Many athletes — even those who don’t have sponsorship arrangements with Maurten — have added it to their routines. But Jumbo-Visma’s top cyclist, Jonas Vingegaard — winner of the last two Tours de France — does not use it. Neither does OAC’s top runner, Yared Nuguse, who tried it a few times in practice but did not use it before any of his four American record races in 2023.
“I’m very low-maintenance and I think my body’s the same,” Nuguse says. “So when I tried to do that, it was kind of like, Whoa, what is this? My whole body felt weird and I was just like, I either did this wrong or this is not for me.”
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How sodium bicarbonate works
The idea that sodium bicarbonate — aka baking soda, the same stuff that goes in muffins and keeps your refrigerator fresh — can boost athletic performance has been around for decades.
“When you’re exercising, when you’re contracting muscle at a really high intensity or a high rate, you end up using your anaerobic energy sources and those non-oxygen pathways,” says Siegler, who has been part of more than 15 studies on sodium bicarbonate use in sport. “And those pathways, some of the byproducts that they produce, one of them is a proton – a little hydrogen ion. And that proton can cause all sorts of problems in the muscle. You can equate that to that sort of burn that you feel going at high rates. That burn, most of that — not directly, but indirectly — is coming from the accumulation of these little hydrogen ions.”
As this is happening, the kidneys produce bicarbonate as a defense mechanism. For a while, bicarbonate acts as a buffer, countering the negative effects of the hydrogen ions. But eventually, the hydrogen ions win.
The typical concentration of bicarbonate in most people hovers around 25 millimoles per liter. By taking sodium bicarbonate in the proper dosage before exercise, Siegler says, you can raise that level to around 30-32 millimoles per liter.
“You basically have a more solid first line of defense,” Siegler says. “The theory is you can go a little bit longer and tolerate the hydrogen ions coming out of the cell a little bit longer before they cause any sort of disruption.”
Like creatine and caffeine, Siegler says the scientific literature is clear when it comes to sodium bicarbonate: it boosts performance, specifically during events that involve short bursts of anaerobic activity. But there’s a catch.
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Bicarb without the cramping
Sodium bicarbonate has never been hard to find. Anyone can swallow a spoonful or two of baking soda with some water, though it’s not the most appetizing pre-workout snack. The problem comes when the stomach tries to absorb a large amount of sodium bicarbonate at once.
“You have a huge charged load in your stomach that the acidity in your stomach has to deal with and you have a big shift in the partial pressure of carbon dioxide across the gut,” Siegler says. “And that’s what gives you the cramping.”
A few years ago, Maurten was trying to solve a similar problem for marathoners trying to ingest large amounts of carbohydrates during races. The result was their carbohydrate drink, which relies on something called a hydrogel to form in the stomach. The hydrogel resists the acidity of the stomach and allows the carbohydrates to be absorbed in the intestine instead, where there is less cramping.
“We thought, okay, we are able to solve that one,” Reuterswärd says. “Could we apply the hydrogel technology to something else that is really risky to consume that could be beneficial?”
For almost four years, Maurten researched the effects of encapsulating sodium bicarbonate in hydrogels in its Swedish lab, conducting tests on middle-distance runners in Gothenburg. Hydrogels seemed to minimize the risk, but the best results came when hydrogels were paired with microtablets of sodium bicarbonate.
The result was the Maurten Bicarb System — “system,” because the process for ingesting it involves a few steps. Each box contains three components: a packet of hydrogel powder, a packet of tiny sodium bicarbonate tablets, and a mixing bowl. Mix the powder with water, let it stand for a few minutes, and sprinkle in the bicarb.
Maurten’s bicarb mix is eaten with a spoon but not chewed
The resulting mixture is a bit odd. It’s gooey. It’s gray. It doesn’t really taste like anything. It’s not quite liquid, not quite solid — a yogurt-like substance flooded with tiny tablets that you eat with a spoon but swallow like a drink.
The “swallow” part is important. Chew the tablets and the sodium bicarbonate will be absorbed before the hydrogels can do their job. Which means a trip to the toilet may not be far behind.
When Maurten launched its Bicarb System to the public in February 2023, it did not have high expectations for sales in year one.
“It’s a niche product,” Reuterswärd says. “From what we know right now, it maybe doesn’t make too much sense if you’re an amateur, if you’re just doing 5k parkruns.”
But in March, Maurten’s product began making headlines in cycling when it emerged that it was being used by Team Jumbo-Visma, including by stars Wout van Aert and Primož Roglič. Sales exploded. Because bicarb dosage varies with bodyweight, Maurten’s system come in four “sizes.” And one size was selling particularly well.
“If you’re an endurance athlete, you’re around 60-70 kg (132-154 lbs),” Reuterswärd says. “We had a shortage with the size that corresponded with that weight…The first couple weeks, it was basically only professional cyclists buying all the time, massive amounts. And now we’re seeing a similar development in track & field.”
If there was a “Jumbo-Visma” effect in cycling, then this summer there was a “Jakob Ingebrigtsen” effect in running.
Ingebrigtsen is widely believed to use bicarb; Nuguse tried it in 2023 but did not like it (Kevin Morris photo)
To be clear: there is no official confirmation that Ingebrigtsen uses sodium bicarbonate. His agent, Daniel Wessfeldt, did not respond to multiple emails for this story. When I ask Reuterswärd if Ingebrigtsen has used Maurten’s product, he grows uncomfortable.
“I would love to be very clear here but I will have to get back to you,” Reuterswärd says (ultimately, he was not able to provide further clarification).
But when Maurten pitches coaches and athletes on its product, they have used data from the past two years on a “really good” 1500 guy to tout its effectiveness, displaying the lactate levels the athlete was able to achieve in practice with and without the use of the Maurten Bicarb System. That athlete is widely believed to be Ingebrigtsen. Just as Ingebrigtsen’s success with double threshold has spawned imitators across the globe, so too has his rumored use of sodium bicarbonate.
Grijalva says he started experimenting with sodium bicarbonate “because everybody’s doing it.” And everybody’s doing it because of Ingebrigtsen.
“[Ingebrigtsen] was probably ahead of everybody at the time,” Grijalva said. “Same with his training and same with the bicarb.”
OAC coach Dathan Ritzenhein took sodium bicarbonate once before a workout early in his own professional career, and still has bad memories of swallowing enormous capsules that made him feel sick. Still, he was willing to give it a try with his athletes this year after Maurten explained the steps they had taken to reduce GI distress.
“Certainly listening to the potential for less side effects was the reason we considered trying it,” says Ritzenhein. “I don’t know who is a diehard user and thinks that it’s really helpful, but around the circuit I know a lot of people that have said they’ve [tried] it.”
Coach/agent Stephen Haas says a number of his athletes, including Gourley, 3:56 1500 woman Katie Snowden, and Worlds steeple qualifier Isaac Updike, tried bicarb this year. In the men’s 1500, Haas adds, “most of the top guys are already using it.”
Yet 1500-meter world champion Josh Kerr was not among them. Kerr’s nutritionist mentioned the idea of sodium bicarbonate to him this summer but Kerr chose to table any discussions until after the season. He says he did not like the idea of trying it as a “quick fix” in the middle of the year.
“I review everything at the end of the season and see where I could get better,” Kerr writes in a text to LetsRun. “As long as the supplement is above board, got all the stamps of approvals needed from WADA and the research is there, I have nothing against it but I don’t like changing things midseason.”
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So does it actually work?
Siegler is convinced sodium bicarbonate can benefit athletic performance if the GI issues can be solved. Originally, those benefits seemed confined to shorter events in the 2-to 5-minute range where an athlete is pushing anaerobic capacity. Buffering protons does no good to short sprinters, who use a different energy system during races.
“A 100-meter runner is going to use a system that’s referred to the phosphagen or creatine phosphate system, this immediate energy source,” Siegler says. “…It’s not the same sort of biochemical reaction that eventuates into this big proton or big acidic load. It’s too quick.”
But, Siegler says, sodium bicarbonate could potentially help athletes in longer events — perhaps a hilly marathon.
“When there’s short bursts of high-intensity activity, like a breakaway or a hill climb, what we do know now is when you take sodium bicarbonate…it will sit in your system for a number of hours,” Siegler says. “So it’s there [if] you need it, that’s kind of the premise behind it basically. If you don’t use it, it’s fine, it’s not detrimental. Eventually your kidneys clear it out.”
Kiptum used bicarb during his marathon WR in Chicago (Kevin Morris photo)
Even Reuterswärd admits that it’s still unclear how much sodium bicarbonate helps in a marathon — “honestly, no one knows” — but it is starting to be used there as well. Kenya’s Kelvin Kiptum used it when he set the world record of 2:00:35 at last month’s Chicago Marathon; American Molly Seidel also used it in Chicago, where she ran a personal best of 2:23:07.
Siegler says it is encouraging that Maurten has tried to solve the GI problem and that any success they experience could spur other companies to research an even more effective delivery system (currently the main alternative is Amp Human’s PR Lotion, a sodium bicarbonate cream that is rubbed into the skin). But he is waiting for more data before rendering a final verdict on the Maurten Bicarb System.
“I haven’t seen any peer-reviewed papers yet come out so a bit I’m hesitant to be definitive about it,” Siegler said.
Trent Stellingwerff, an exercise physiologist and running coach at the Canadian Sport Institute – Pacific, worked with Siegler on a 2020 paper studying the effect of sodium bicarbonate on elite rowers. A number of athletes have asked him about the the Maurten Bicarb System, and some of his marathoners have used the product. Like Siegler, he wants to see more data before reaching a conclusion.
“I always follow the evidence and science, and to my knowledge, as of yet, I’m unaware of any publications using the Maurten bicarb in a double-blind, placebo-controlled clinical trial,” Stellingwerff writes in a text to LetsRun. “So without any published data on the bicarb version, I can’t really say it does much.”
The closest thing out there right now is a British study conducted by Lewis Gough of Birmingham City University and Andy Sparks of Edge Hill University. In a test of 10 well-trained cyclists, Gough and Sparks found the Maurten Bicarb System limited GI distress and had the potential to improve exercise performance. Reuterswärd says the study, which was funded by Maurten, is currently in the review process while Gough and Sparks suggested further research to investigate their findings.
What about the runners who used sodium bicarbonate in 2023?
Klecker decided to give bicarb a shot after Maurten made a presentation to the OAC team in Boulder earlier this year. He has run well using bicarb (his 10,000 pb at The TEN) and without it (his 5,000 pb in January) and as Klecker heads into an Olympic year, he is still deciding whether the supposed benefits are worth the drawbacks, which for him include nausea and thirst. He also says that when he has taken the bicarb, his muscles feel a bit more numb than usual, which has made it more challenging for him to gauge his effort in races.
“There’s been no, Oh man I felt just so amazing today because of this bicarb,” Klecker says. “If anything, it’s been like, Oh I didn’t take it and I felt a bit more like myself.”
Klecker also notes that his wife and OAC teammate, Sage Hurta-Klecker, ran her 800m season’s best of 1:58.09 at the Silesia Diamond League on July 16 — the first race of the season in which she did not use bicarb beforehand.
A number of athletes in Mike Smith‘s Flagstaff-based training group also used bicarb this year, including Grijalva and US 5,000 champion Abdihamid Nur. Grijalva did not use bicarb in his outdoor season opener in Florence on June 2, when he ran his personal best of 12:52.97 to finish 3rd. He did use it before the Zurich Diamond League on August 31, when he ran 12:55.88 to finish 4th.
“I want to say it helps, but at the same time, I don’t want to rely on it,” Grijalva says.
Almost every OAC athlete tried sodium bicarbonate at some point in 2023. Ritzenhein says the results were mixed. Some of his runners have run well while using it, but the team’s top performer, Nuguse, never used it in a race. Ritzenhein wants to continue testing sodium bicarbonate with his athletes to determine how each of them responds individually and whether it’s worth using moving forward.
That group includes Alicia Monson, who experimented with bicarb in 2023 but did not use it before her American records at 5,000 and 10,000 meters or her 5th-place finish in the 10,000 at Worlds.
“It’s not the thing that’s going to make or break an athlete,” Ritzenhein says. “…It’s a legal supplement that has the potential, at least, to help but it doesn’t seem to be universal. So I think there’s a lot more research that needs to be done into it and who benefits from it.”
The kind of research scientists like Stellingwerff want to see — double-blind, controlled clinical trials — could take a while to trickle in. But now that anyone can order Maurten’s product (it’s not cheap — $65 for four servings), athletes will get to decide for themselves whether sodium bicarbonate is worth pursuing.
“The athlete community, obviously if they feel there’s any sort of risk, they’re weighing up the risk-to-benefit ratio,” Siegler said. “The return has got to be good.”
Grijalva expects sodium bicarbonate will become part of his pre-race routine next year, along with a shower and a cup of coffee. Coffee, and the caffeine contained wherein, may offer a glimpse at the future of bicarb. Caffeine has been widely used by athletes for longer than sodium bicarbonate, and the verdict is in on that one: it works. Yet plenty of the greats choose not to use it.
Nuguse is among them. He does not drink coffee — a fact he is constantly reminded of by Ritzenhein.
“I make jokes almost every day about it,” Ritzenhein says. “His family is Ethiopian – coffee tradition and ceremony is really important to them.”
Ritzenhein says he would love it if Nuguse drank a cup of coffee sometime, but he’s not going to force it on him. Some athletes, Ritzenhein says, have a tendency to become neurotic about these sorts of things. That’s how Ritzenhein was as an athlete. It’s certainly how Ritzenhein’s former coach at the Nike Oregon Project, Alberto Salazar, was — an approach that ultimately earned Salazar a four-year ban from USADA.
Ritzenhein says he has no worries when it comes to any of his athletes using sodium bicarbonate — Maurten’s product is batch-tested and unlike L-carnitine, there is no specific protocol that must be adhered to in order for athletes to use it legally under the WADA Code. Still, there is something to be said for keeping things simple.
“Yared knows how his body feels,” Ritzenhein says. “…He literally rolls out of practice and comes to practice like a high schooler with a Eggo waffle in hand. Probably more athletes could use that kind of [approach].”
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*MB: Did you know there’s a pill that supposedly over half the distance medallists used in 2023?
