John Korir Just Crushed the Boston Course Record (And Left Us Looking at His Shoes)
John Korir dropped a historic 2:01:52 at the 2026 Boston Marathon. Here’s a look at his insane negative split and the ASICS prototype on his feet.
· 4 min read · Athletics News
The Boston Marathon course isn't built for world records.
With its rolling Newton hills and elevation profiles that rip a runner's quads to shreds by mile 21, Boston is a tactical war of attrition, not a flat runway for blistering splits. At least, that's what we believed until John Korir decided to rewrite the manual on Patriots' Day 2026.
Korir broke the tape in an unthinkable 2:01:52, absolutely obliterating the course record. But it wasn't just the final time that turned heads. It was how he ran the race, who he ran it against, and the unreleased foam slabs glued to his feet.
A Negative Split That Defies Logic
Most mortals target a positive or even split at Boston. You bank a little time on the early downhills, suffer through Heartbreak Hill, and try to hold whatever form you have left for the final miles.
Korir did the exact opposite. He hit the halfway mark at 1:01:50, running alongside a deep pack. Then, just as the elevation started demanding its toll, he put his foot down. His second-half split was a scorching 60:02.
Think about that. Running 60 minutes for a half marathon is a world-class achievement on a flat course. Dropping a 60-minute half on the back end of Boston is frankly insane. To put the nail in the coffin, Korir surged when the pack reached the dreaded Newton hills near the 32k mark. He closed out the final 2.195 kilometers in just 6:04. He literally dropped the fastest marathoners in the world on the hardest part of the course.
The Deepest Field in Boston History
Korir's performance forced everyone else to run out of their minds just to keep the lead vehicle in sight. For the very first time in Boston Marathon history, the top three finishers in the men's elite race all ran under 2:03.
Alphonce Felix Simbu and former champion Benson Kipruto chased Korir to the bitter end. And we have to give a massive nod to Zouhair Talbi, who threw down a 2:03:45 to claim fifth place - the fastest marathon time ever recorded by an American man at Boston. On the women's side, Sharon Lokedi proved last year wasn't a fluke, successfully defending her title in a dominant 2:18:51.
Let's Talk About the Protocol: The ASICS Prototype
You can't have a modern marathon result without a super shoe debate. Korir was spotted wearing an unreleased ASICS Metaspeed Sky prototype.
This isn't actually the first time we've seen this shoe. He raced in a similar prototype at Boston last year, which industry insiders suspect is the "ASICS MS5 Type-P" currently hiding on the World Athletics approved list. While we don't have the exact stack height or foam composition yet, it is clear ASICS is continuing to tweak the rocker geometry and foam density for their elite roster. Whether this prototype will hit the retail market for the rest of us remains the big question.
What You Can Learn from Korir's Race
You might not be running a two-hour marathon, but there is a major takeaway here for your next block.
Korir didn't panic and try to force the pace when the pack was sitting comfortably at the 1:01:50 half mark. He waited. He trusted his fitness on the hills, and he conserved enough energy to attack when the environment became brutal.
For your next race - whether it is a local 10K or a major marathon - discipline in the first half dictates your survival in the second. Respect the course early, and you will have the legs to race the people around you when it counts.
*Did you watch the 2026 Boston Marathon? Drop your thoughts on Korir's crazy negative split in the comments below, or check out our [marathon training plans](/runs) to start preparing for your own race day.*