The shoes were three days old. Properly three days. Adidas had drip-fed a sliver of stock into the world on Thursday, then watched their man Sabastian Sawe lace them up on Sunday morning in Greenwich and use them to do something nobody had ever done before in a sanctioned race.

He won the London Marathon in 1:59:30. The first legal sub-two-hour marathon in human history. The trainers on his feet, the Adidas Adizero Adios Pro Evo 3, weighed ninety-seven grams. A pair of them comes in lighter than a king-size Mars bar.

Twenty-three years ago Paula Radcliffe ran 2:15:25 in London in a pair of Nike racing flats. Modest stack. No plate. Today's elite shoes sit right on the legal limit, a forty-millimetre slab of foam with a curved carbon plate buried in the middle that springs the foot forward at every stride. Adidas claim the Evo 3 is thirty per cent lighter than the Evo 2, returns eleven per cent more energy at the forefoot, and improves running economy by 1.6 per cent. The upper, the brand says, was inspired by kitesurfing sails.

Behind Sawe, in the same shoe, came his Ethiopian training partner Yomif Kejelcha, who clocked 1:59:41 in his marathon debut. Two men under two hours in a single race. The number both of them ran was a clean thirty-five seconds inside the late Kelvin Kiptum's 2:00:35, set in Chicago in 2023. Third was Uganda's Jacob Kiplimo in 2:00:28, the only podium finisher not in three stripes. He wore an unreleased Nike Alphafly 4 prototype.

There is a footnote here too elegant to leave out. The foam that started all of this was not invented in Beaverton or Herzogenaurach. It was made in Croydon. Zotefoams, a hundred-year-old company on Mitcham Road, found a way to expand a polymer called Pebax into a featherweight foam and sold it as ZOTEK PEBA. Nike licensed it, badged it ZoomX, and built the Vaporfly 4% of 2017 around it. Every record that has fallen since has been chasing what that south London foam unlocked. Kiplimo's third place on Sunday was run on its direct descendant. Sawe's foam, Adidas's in-house Lightstrike Pro Evo, is the German answer to it. The record fell in London. The chemistry that made the record thinkable was born in London. The two facts are not the same fact, but they sit together pleasingly.

The shoe is a piece of all this, but it is not the whole story. Eliud Kipchoge, the only other man to have run a marathon under two hours, did so in October 2019 in Vienna in a closed event with rotating pacers and a laser beam projected onto the road in front of him, wearing prototype Nikes built around that Croydon foam. He ran 1:59:40. The IAAF, as it was, refused to ratify it. Asked afterwards whether the shoes had done the work, he was blunt. "It is my legs that are still doing the running," he said.

adidas

Within three years of the Vaporfly's release every brand had a version. Asics now sell the Metaspeed Sky Tokyo for around £270. Saucony's Endorphin Pro 5 sits a little under that. Nike's projected Alphafly 4 retail is closer to £300. Adidas put the Evo 3 out at five hundred dollars, available in a trickle, designed for perhaps three races before the upper gives up the ghost. The shoe is a single-use object dressed up as footwear. World Athletics regulates the stack height at forty millimetres and limits each shoe to a single rigid plate. Sawe's pair sat right on the line.

The pace tells you what the shoes are doing. He came through halfway under an hour. He held 4:34 a mile for two hours and never really looked like he was working that hard. Kejelcha, on debut, was within touching distance the entire way and only let go inside the final mile.

In the elite women's race Tigst Assefa wore the same Evo 3 and took the women's world record down to 2:15:41, ten seconds inside her own previous mark. Hellen Obiri ran 2:15:53. Joyciline Jepkosgei was two seconds further back. Three women under 2:16 in a single race had never happened either.

Sawe, asked at the line what had changed, did not mention the trainers. "I want to thank the crowds," he said. "You feel so happy and strong and pushing. What comes for me today is not for me alone but all of us in London."

adidas

The shoe does not run the race. It does, however, decide what kind of race is now possible. Ninety-seven grams. One hour, fifty-nine minutes, thirty seconds. A barrier that was supposed to take a generation to fall, gone on a Sunday in April, on chemistry first cooked up off the A23.

All images supplied by adidas