Why Sawe's Sub-2 Marathon Counts and Kipchoge's Never Did

Sixty-five seconds. That is how much time Kenya's Sabastian Sawe cut from the marathon world record at the TCS London Marathon on 26 April 2026, crossing the line in 1:59:30 to become the first man to break two hours for the distance in a race that counts. Ethiopia's Yomif Kejelcha, making his marathon debut, followed eleven seconds later in 1:59:41, the second-fastest time ever recorded.

Seven years earlier, in Vienna, Eliud Kipchoge ran 1:59:40 and much of the world treated it as history anyway. It was never a world record and never will be. The gap between those two performances has nothing to do with who is the better runner. It comes down to two separate rulebooks World Athletics has spent the better part of a decade writing: one covering who is allowed to help a runner along the course, the other covering what a runner is allowed to strap to their feet. Sawe's race in London is the first time both have lined up cleanly.

Why doesn't Kipchoge's 1:59:40 count as a world record?

Kipchoge's 2019 run, the INEOS 1:59 Challenge, was built from the ground up to break two hours: a closed loop in Vienna's Prater park, a hand-picked flat course, an out-front pace car projecting laser lines onto the road, and a rotating relay of roughly 40 elite pacemakers who swapped in and out in formation around him. Neither that event nor Kipchoge's earlier attempt in Monza carried World Athletics sanctioning, because record-eligible races don't allow pacers to rotate in relay teams or shield a single athlete for the entire distance.

Sawe's London run used the format every World Marathon Major uses: a handful of pacemakers who dropped off well before the finish, running inside a full field of competitors on a certified point-to-point course, open to anyone who qualified. According to LetsRun's breakdown of the race, the last pacer stepped off the course just after 25 kilometers. From there, Sawe ran his fastest sections of the day, a 13:54 five-kilometer split and then a 4:12 mile, the fastest mile ever recorded in a marathon, entirely on his own legs, competing against Kejelcha and Uganda's Jacob Kiplimo rather than a hired escort. That distinction, run alone against real rivals instead of shepherded by a relay of rabbits, is what makes a fast marathon eligible for the record book at all.

What are World Athletics' rules on marathon shoes?

The second rulebook is newer, and it exists because of exactly this kind of finish. After Nike's Vaporfly line, introduced in 2016, coincided with a wave of record-breaking times, World Athletics amended its technical rules in January 2020, imposing an outright limit: no road shoe may have a sole thicker than 40 millimeters, and none may contain more than one rigid embedded plate. Any new design also has to sit on the open retail market, available for anyone to buy, for four months before an athlete can race in it; otherwise it is treated as an unreleased prototype and banned outright.

"It is not our job to regulate the entire sports shoe market but it is our duty to preserve the integrity of elite competition by ensuring that the shoes worn by elite athletes in competition do not offer any unfair assistance or advantage."

Sebastian Coe, World Athletics president

The rule was a compromise, and everyone involved knew it at the time. An analysis published shortly after the amendment pointed out that a 2017 study had already found the new foam-and-carbon construction made runners roughly 4% more efficient than in earlier racing flats, a real physiological edge and not a placebo, while still leaving every existing world record on the books untouched. World Athletics drew a line forward rather than erasing what had already happened.

Did Sawe's shoes make the difference?

Four of the top five finishers in London, including Sawe, wore adidas. His pair, the Adizero Adios Pro Evo 3, was used in a marathon for the first time that morning. A men's size 9 weighs just 97 grams, about 30% lighter than its predecessor, while still carrying a 39-millimeter stack height, a single millimeter under the legal limit. Jacob Kiplimo, third in a Ugandan record 2:00:28, wore Nike.

Whether the shoe explains the result is a genuinely open question, and the people closest to the data are careful not to overclaim it. LetsRun noted that a study cited by the Wall Street Journal found runners in a shoe 3.5 ounces lighter than normal could gain roughly 57 seconds over a marathon, almost exactly the 58-second margin by which Sawe beat Kiplimo. "We don't have the data to state that as a fact," the site wrote, "but it may not have been a coincidence."

Correlation, not proof.

"I feel good, I'm so happy. It is a day to remember for me," Sawe said afterward, adding that four months of training had built toward exactly this result. His time still needs to clear World Athletics' standard ratification process, which checks drug testing, course measurement and equipment compliance, before it becomes the official record: a formality at this level of scrutiny, but a real one.

None of this is unique to running. Sports keep writing rules to decide which version of a record counts, and the logic shows up everywhere once you look for it. It's why championship boxing shrank from 15 rounds to 12, and it's the same instinct behind how referees calculate stoppage time at the World Cup: a constant negotiation between what athletes can now do and what a sport is willing to call fair. Wikipedia's entry on super shoes notes that 15 of the 20 fastest marathons ever run happened since 2018, which is either a golden age of distance running or a referendum on footwear, depending on who's arguing. Sawe's 1:59:30 didn't settle that argument. It just happened to be run entirely within the rules that exist to have it.