When Grant Fisher stepped off the track at Boston University on Feb. 14, it wasn’t entirely a shock that the American distance runner had just broken the world record for the indoor 5,000 meters.
For one thing, he was in great shape. Only six days earlier, Fisher, 27, who was coming off a breakout season in which he earned two silver medals at the Paris Olympics, had also broken the world record at 3,000 meters in New York City. Larger trends were also at play: He was running on one of the fastest tracks in the world, wearing Nike spikes whose carbon plates and advanced foams helped return energy with every stride.
Yet in Boston, when Fisher was asked about the factors that had led to his pair of world records, he acknowledged one so surprisingly simple that it’s probably in your kitchen.
He’d recently begun taking baking soda.
“I think it makes an impact, and if that impact is 1%, that would be massive,” Fisher told reporters. “It’s probably more like 0.1%, if there is one. And if it is just mental, then I’ll take that, too.”
Fisher is among the many professional runners in recent years to embrace baking soda — known within the sport by its scientific name, sodium bicarbonate, or simply “bicarb” — as a legal means of running faster times than ever. The use of a bicarbonate “system” sold by Maurten, a Swedish company, has become so widespread that at track and field’s world championships in 2023, two-thirds of all medalists from 800 to 10,000 meters were using it. At the Olympics last summer, more than two-thirds of all running medalists were using it — “and in some cases, all the finalists were using it,” the company told NBC News.
In an eight-day span in February, seven of the sport’s world records in races ranging from the 1,500 meters to the road half-marathon were smashed. The rapid-fire rewriting of professional running’s record book can be traced to many reasons, from high-tech advancements leading to faster shoes and tracks, quicker recovery and better coaching.
The combination has convinced Chris Woods, the head track coach at Mississippi State University, that not only “a lot of world records are in jeopardy here in the very near future” but that even times that once appeared unthinkable could now be possible, such as the record of 4:07 in the women’s mile.
“In my lifetime, in your lifetime, I do believe we’ll see a woman break 4 minutes,” Woods said.
But increasingly, runners such as Marco Arop, the 2023 world champion at 800 meters from Canada, whom Woods coaches, are also turning to “bicarb” for an edge.
Intense periods of exercise create a build-up of hydrogen ions in muscles, leading to acidity that can increase fatigue and create the “burning” sensation felt during hard exercise. As a base, sodium bicarbonate acts as a “buffer” that counters the acidity. Taking sodium bicarbonate doesn’t run afoul of World Anti-Doping Agency rules; in fact, even World Athletics, track and field’s global governing body, has described it as an “established performance supplement.”
The benefits of “bicarb” have been known for decades, said Steve Magness, a coach and former elite runner who has written multiple books about performance. But athletes have been wary of it for just as long for an often unpleasant reason: The odds of a performance boost had to be weighed against the risk of race-wrecking gastrointestinal distress.
“It didn’t work very well because there was a high percentage of people that just couldn’t even line up for the race or the time trial because it just tore apart your stomach,” Magness said.
Fisher had heard so many “horror stories” of nausea, vomiting or diarrhea from using bicarbonate that he waited until this winter, after the all-important Olympics cycle, to test out a “bicarb” mixture in training. His stomach handled it fine, he said. And that may have been because in recent years, bicarb has hit a turning point.
Maurten, the Swedish company, has found a way to encase small tablets of bicarbonate into a gooey, soup-like hydrogel that guides them through the stomach and into the intestine, where the bicarbonate is dissolved and absorbed with less potential nausea, vomiting or diarrhea, according to the company. Side effects of taking sodium include water retention and weight gain, and regularly increasing sodium intake may lead to an increase in blood pressure, the company says.
Maurten’s credibility was boosted when famed marathon runner Eliud Kipchoge used its products to set multiple world records. Other Maurten users include Keely Hodgkinson, the Olympic champion at 800 meters.
Beyond the hydrogel, however, bicarb may have become more palatable for elite runners recently for another reason. Just as the Paris Olympics began, a study in the European Journal of Applied Physiology upended a long-held belief that sodium bicarbonate was most effective as a buffer in shorter competitions, lasting up to around 10 minutes.
When researchers at Edge Hill University in the United Kingdom gave Maurten’s bicarbonate product to male cyclists during a much longer, 40-kilometer time trial — nearly the length of a marathon — they measured a 1.4% boost in the cyclists’ performance, with minimal stomach issues. In practice, it meant cyclists using the bicarbonate were nearly 1 minute faster over about an hour of riding, said Eli Spencer Shannon, a Ph.D. candidate who led the study.
“I would classify that as small but meaningful,” Shannon said.
The findings, Shannon said, should spark more research. Bicarb isn’t “one size fits all,” he said, because each person’s stomach distress can vary and because baking soda’s effectiveness as a buffer depends on how hard an athlete can push; harder exercise produces more hydrogen ions in the muscle that the bicarbonate can then remove.
Still, Shannon was surprised by some of his study’s findings, such as that the riders using bicarbonate also were able to go faster without a change in their heart rate or the maximum amount of oxygen they were able to use during exercise, known as VO₂.
“What that’s saying is that you’re able to sort of work harder but have less cardiovascular strain and have a better performance improvement in comparison to a placebo, which was really interesting,” Shannon said. “That suggests increased [muscle] contractility, which has never been seen, at this duration and at this intensity.”
Not all of track’s recent world-record holders incorporate baking soda as a new tool in their training. American Yared Nuguse, who broke the indoor mile record on Feb. 8, only for Norwegian rival Jakob Ingebrigtsen to reset it five days later, has said he doesn’t use bicarbonate because of its taste. But some of the world’s fastest have taken note.
Two days before last summer’s Olympic semifinal in the men’s 800 meters, Arop, a former basketball player who became the world champion at 800 meters for Canada, turned to Woods in France with less a question than a statement. He was set on trying bicarb. The 800 meters was in the middle of one of the fastest years in the sport’s history, and Arop knew several of his competitors had used it with success.
“This is the pinnacle of our sport, and I don’t think he wanted to leave anything to chance,” Woods said. “And if there was a way to give a 1% advantage, that’s what he was going to do. That’s what he believed. And the results we were pretty happy with.”
Woods didn’t know much about bicarb until Arop raised the topic in France, but he said he now believes there are scientific benefits.
“Is there a mental component to it? I would say absolutely,” he said. “But I don’t think this is a placebo.”
Arop went on to earn the silver medal in the fourth-fastest time in 800 meters history, edged from the gold by just one one-hundredth of a second by Kenya’s Emmanuel Wanyonyi — who also was using Maurten’s bicarbonate in Paris, according to the company. The 800-meter world record, set in 2012, could be the next to go down, with Wanyonyi just two-tenths of a second behind. After the race, Arop said he believed his last-minute addition of sodium bicarbonate had “definitely played a factor” in his personal-best time.
“Everybody else is using it, and it’s been working wonders,” Arop said in August.
Not everybody uses it. Bicarbonate is just one factor of many that have sparked what Woods called “the golden era of track and field when it comes to running fast times,” a boom he likened to the NBA in the 1980s, when the talent of Larry Bird and Magic Johnson, coupled with better technology and rules changes, boosted its popularity.
A “shoe war,” as Magness said, has broken out in a race to develop shoes that return the most energy using bulky yet light foams and carbon-fiber plates. Under athletes’ feet, the physics of indoor tracks are also fueling faster times. The indoor track at Boston University, in particular, has become a destination because its wide, banked corners help runners ricochet around turns, and its above-ground frame made of wood and plywood can return energy like a mini-trampoline more than an outdoor track, where a rubber surface is poured over a concrete base.
When Magness was running two decades ago, an information gap left him to wonder how East African competitors were training. Social media and the internet have opened access to other training methods and better coaching that don’t burn out young runners and created a bigger pool of strong runners, Magness said. Those young athletes are watching peers run faster than ever and believing confidently they can, too.
They are powered by cutting-edge advancements Roger Bannister could only have dreamed of when he was chasing the first sub-4-minute mile — along with a basic household item, too.
“What the last couple years have done is kind of shift that mindset of, like, here’s the past and here’s what we were able to do,” Magness said. “But now the game has changed.”
