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Camille Herron runs 435K to break 48-hour world record in Australia

Competing at the Sri Chinmoy 48 Hour Festival in Canberra, Herron went farther than all but two runners in ultrarunning history

Camille Herron Photo by: Lululemon

American ultrarunner Camille Herron set an amazing world record on Saturday after she ran a mind-boggling 435.336K at the Sri Chinmoy 48 Hour Festival in Canberra, Australia. Herron’s final mileage tally won her the women’s world record and the outright American record (she beat the men’s national best by 14K), and now only two runners—Andrii Tkachuk and Yiannis Kouros—have run farther than her over a 48-hour period. Herron won the 48-hour event in Australia by more than 130K. 

Running Sri Chinmoy 

Ahead of her run at the Sri Chinmoy Festival, Herron was open about her goal to break the 48-hour world record. In February, she told Canadian Running that she planned to “focus on world records” this season, specifically mentioning the 48-hour mark. Just before she kicked things off in Canberra, she tweeted “let’s go where no woman has ever gone before.” 

The distance Herron aimed to beat was 411K, the world record set by Scottish ultrarunner Joasia Zakrzewski in Taiwan in February. In that run, Zakrzewski broke the world record of 403K set by Poland’s Patrycja Bereznowska in 2022 and became just the second woman to crack 400K in a 48-hour race. Herron is now the third woman to break that barrier, and she added a whopping 24K to Zakrzewski’s record. 

Herron got to a speedy start in Canberra (where she and the other competitors ran laps of a 400m track), covering the first 100K in 8:49:41 (5:18 per-kilometre pace). By the time she hit the 100-mile mark, she had been running for just over 14 hours and 40 minutes. This would have been a great result on its own, as only a handful of women have ever run 100 miles faster (Herron owns the 100-mile women’s world record of 12:41:10), but Herron kept on running for another 33 hours. Over that next day and a bit, she ran lap after lap of the track and covered another 270K, eventually crossing the finish line with a massive world record. 

A huge record 

Herron’s new PB beat Olivier Leblond‘s American 48-hour record of 421K, and it smashed the national women’s record of 391K, which belonged to Marisa Lizak. Seeing as she ran so many kilometres, it may seem funny to be so specific with Herron’s record of 435.336K, but it turns out that precision is extremely necessary in this case, as she came incredibly close to eclipsing Tkachuk’s 435.446K result, which he ran in his home country of Ukraine in 2021.

Tkachuk’s PB is the  seventh-farthest 48-hour result in history, behind Kouros’s six best runs. Kouros, who hails from Greece, owns the 48-hour world record of 473.495K. Herron’s run in Australia gives her the eighth-farthest result of any runner in 48-hour racing history. 

For full results from the Sri Chinmoy 48 Hour Festival, click here

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