VIENNA On a misty Saturday morning in Vienna, on a course specially chosen for speed, in an athletic spectacle of historic proportions, Eliud Kipchoge of Kenya ran 26.2 miles in a once-inconceivable time of 1 hour 59 minutes 40 seconds.
In becoming the first person to cover the marathon distance in less than two hours, Kipchoge, 34, achieved a sports milestone granted almost mythical status in the running world, breaking through a temporal barrier that many would have deemed untouchable only a few years ago.
Kipchoge, an eight-time major marathon winner and three-time Olympic medalist, pounded his chest twice as he crossed the finish line in Viennas leafy Prater Park, where the majority of the run had unfolded on a long straightaway of recently paved road, with roundabouts on either end.
Cheered on by a thick crowd of spectators, he was lifted into the air by members of his team, including the 41 professional runners who had acted as pacesetters during the run.
For Kipchoge, the feat merely burnished his credentials as the worlds greatest marathoner.
Together, when we run, we can make this world a beautiful world, Kipchoge said after finishing.
For all its magnitude, the accomplishment will be regarded largely as a symbolic one. The eye-popping time, which was 10 seconds quicker than the 1:59:50 time Kipchoge and his team had set out to achieve, will not be officially recognized as a world record because it was not run under open marathon conditions and because it featured a dense rotation of professional pacesetters.
What the event lacked in officially sanctioned gravitas, though, it seemed determined to make up for with theater and grandiose proclamations.
The run, organized by the petrochemical company INEOS, featured a cycle of hype and commercial buildup more reminiscent of a heavyweight prizefight than a road race.
Organizers billed the two-hour mark as the last barrier of modern athletics and tried to get a hashtag, #nohumanislimited, trending on social media.
Kipchoge repeatedly compared a potential sub-two-hour marathon to humanitys first journey onto the surface of the moon.
The pressure was very big on my shoulders, said Kipchoge, who revealed he had received a call from President Uhuru Kenyatta of Kenya the night before the run.
Whatever the scope of the achievement, it required a prodigious amount of planning.
Seeking the most welcoming environment for Kipchoge to attempt such a feat, the events organizers had settled on Vienna: It was not too warm, not too cold and not at all hilly. The altitude, 540 feet above sea level, was just right, and it was only one time zone away from Kipchoges training camp in Kaptagat, Kenya, where he had worked out for the past four months under the guidance of his longtime coach, Patrick Sang.
He had led a monastic existence there, eating, sleeping and exercising for the sole purpose of running fast. To his normal preparations he added workouts focused on core strength in order to lessen the strain on his hamstrings.
On Saturday, Kipchoge showed the subtlest signs of strain on his face in the first half of the run and fell a couple seconds behind his desired pace in a few portions. He ran the final stretches of the marathon with his lips curled into a gentle smile. Afterward, he walked with a barely perceptible limp.
There are no guarantees in sports, Jim Ratcliffe, the billionaire founder of INEOS, said to Kipchoge after the finish. You could have had a bad day. But you had a really good day.
Kipchoge had made an attempt at the two-hour barrier once before. In 2017, in a similar event organized by Nike, he ran a 2:00:25 marathon around an auto racetrack in Monza, Italy. It was by far the fastest marathon ever run, but it was not officially recognized as a world record because it was not run under normal race conditions.
Since then, and in officially sanctioned major marathons, Kipchoge has produced the two fastest times in history, posting a world-record time of 2:01:39 in Berlin in 2018 and 2:02:37 last April in London.
Berlin was about running a world record, Kipchoge said this past week. Vienna is about running and breaking history, like the first man on the moon.
He arrived in Austria on Tuesday, but the exact start date for the attempt was not finalized until the following day, and the precise start time was not settled until Friday afternoon.
What materialized on Saturday was perhaps the most finely tuned, carefully orchestrated marathon-length run in history.
Kipchoge got out of his hotel bed at 4:50 a.m. and had oatmeal for breakfast.
At 8:15 a.m., after a three-hour wait that he called the hardest time ever in my life, he set out from the Reichsbrcke, a picturesque bridge spanning the Danube, and charged across a stretch of downhill road that led him into the park. There, he ran around a 9.6-kilometer flat circuit, more than 90 percent of which unfurled in a straight line. Portions of the road were painted with lines to highlight the fastest possible path.
Kipchoge who wore a white singlet, white sneakers (Nikes, as of yet unreleased to the public, built around a carbon-fiber plate) and white sleeves on his arms had immense support. He ran behind an electric timing car driving 4:34 per mile (with a second car on standby) and with his flock of rotating pacesetters (35 on the course, six on reserve) who happened to include some of the best distance runners in the world, including former world and Olympic gold medalists like Bernard Lagat and Matthew Centrowitz.
Those pacemakers, wearing black jerseys and stern expressions, formed a protective, aerodynamic pocket around Kipchoge, five of them running in front in an open-V formation and two more in the back. They knew exactly where to run thanks to a pattern of thick, green laser beams projected onto the street by the timing car. At predetermined times, the seven pacemakers would make way for another group of seven to slide in and take over.
A team member on a bicycle periodically pedaled into the pack to deliver Kipchoge a carbohydrate-heavy cocktail of gels and fluids.
Looking at the 1:59:40 time, I got so emotional, said Lagat, a two-time Olympic medalist.
Down the final stretch, as it was clear that the milestone was easily in reach, the pacesetters, timing car and accompanying cyclists all peeled away, leaving Kipchoge alone to soak in the shouts and applause of the crowd.
After crossing the finish line, Kipchoge jumped into the arms of his wife, Grace, and children. Through all his years of competition, all the victories and medals and records in his career, this was the first time his family had watched him run in person.
Andrew Keh is an international correspondent, covering sports from Berlin. He has previously covered Major League Baseball and the N.B.A. and has reported from the World Cup and the Olympics. @andrewkeh