Uganda's Joshua Cheptegei shattered the 5km road world record in Monaco on Sunday, shaving 27 seconds off the mark set by Kenya's Rhonex Kipruto last month.
Cheptegei, the 10,000m world champion, crossed the finish line in 12 minutes and 51 seconds in his first race of the year to eclipse Kipruto's effort from the 10K Valencia Ibercaja in Spain last month.
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Kipruto had set the mark en route to the 10km road world record.
“Wow, this is really great. I had sub 13 minutes in my mind today so when my legs felt good during the race, I really decided to go for it,” the 23-year-old Cheptegei said.
"To take this many seconds of the record makes me very happy and is a great first test for me in an important season."
There was one important distinction about Cheptegei’s record run - he completed it with the controversial Nike Vaporfly shoes, which were made famous when they were worn to run the first ever sub-two hour marathon.
For anyone who did a parkrun this weekend, try and get your head around this: Joshua Cheptegei just smashed the 5km world record in 12 minutes and 51 seconds.
(And yes, he was wearing 'those' shoes.)
— Ben Bloom (@benbloomsport) February 16, 2020
On a separate note, it's also another race where it's hard to contextualize the performance because of the Nike shoes, which is a bummer. But Cheptegei is amazing regardless!
— Ben Geman (@Ben_Geman) February 16, 2020
The shoes were deemed legal to compete in by world athletics bodies earlier in February, but World Athletics president Sebastian Coe flagged more research being done into what would be deemed acceptable.
“As we enter the Olympic year, we don’t believe we can rule out shoes that have been generally available for a considerable period of time,” Coe said.
“But we can draw a line by prohibiting the use of shoes that go further than what is currently on the market while we investigate further.”
Frenchman Jimmy Gressier finished second in Monaco with a time of 13:18 to beat the European record of 13:29 set by Julien Wanders in the same race last year.