Ashley Paulson stepped onto a treadmill at 3:46 a.m. on Saturday inside an almost empty convention hall in Boston. Nearly 13 hours later, she stepped off having run 100 miles in 12:47:10, a time that is pending ratification as the new women’s treadmill world record. The previous mark of 14:15:08 fell by close to an hour and a half.
Paulson, who lives in St. George, Utah, ran the effort at the Boston Marathon Expo inside the John B. Hynes Veterans Memorial Convention Center. She finished just after 4:30 p.m. in front of several hundred spectators, many of whom stopped by the treadmill on their way through the hall ahead of Monday’s race. Her average pace worked out to about 4:46 per kilometre, or 7:40 per mile.
Her husband, Matt, handled the crewing. He passed her bottles through the morning and afternoon while she aimed to take in roughly 300 calories and 80 to 90 grams of carbohydrate each hour, sticking closely to her ultra-fueling plan. She took about five short bathroom breaks during the attempt and otherwise stayed on the belt.
“Our goal is to run about 13:30, because we really had no idea how fast I could run while taking potty breaks, so to be able to break 13 hours was really amazing … but that hurt!” Paulson said afterward. “The crowd of people and all of their support really helped me a lot today. That would’ve been really difficult if I was by myself doing that. It feels incredible to get it done, but I did not do it by myself. It took an army to get there.”
Family in the mix
Paulson is a mother of four and a grandmother of one. Her son Max was at the expo holding an iPad that livestreamed the final miles through FaceTime to two of the Paulsons’ other children back in Utah. The livestream, the crowd noise, and the knowledge that she was closing in on the record all hit her at once in the final hour.
“Having everyone on hand to be a part of it was really great, but it was also very emotional,” she said. “I don’t know if you’ve ever tried to run while you’re crying, but it’s really hard.”
Matt Paulson said the toughest stretch came well before spectators arrived. The expo doors opened several hours after Ashley started running, leaving her with a small crew in a quiet hall for the first section of the effort.
“She’s someone who really feeds off a crowd, so I predicted the hardest part of this would be the six hours before the expo actually opened,” he said. “There were just a handful of us here, and we could only generate so much energy. But once the expo opened, the energy increased because people would come up to her and tell her how she has inspired them.”
A run at a record that is already hers
The treadmill effort is not the first 100-mile record Paulson has broken this year. On February 20, she ran 12:19:34 at the Jackpot 100 Mile in Henderson, Nevada, which doubled as the USATF 100-Mile Championships. That time took more than 17 minutes off the previous road world record of 12:37:04, set by Ireland’s Caitriona Jennings at the 2025 Tunnel Hill 100 Mile. Paulson won the women’s race at Jackpot and placed second overall.
She mentioned that effort in the lead-up to Saturday’s run. “Dialing everything in has been key,” she wrote on Instagram. “After how smooth things went at Jackpot 100, I’m sticking with what works—just taking it to the treadmill this time.”
Paulson spent her 30s racing as a professional triathlete before moving to ultrarunning. Since then, she has won Badwater 135 twice. In 2022 she took the women’s title and the course record at the 135-mile race through Death Valley, which is billed as the world’s toughest footrace. In 2023 she returned and beat her own mark by two and a half hours, winning the overall race as well.
Monday and beyond
Paulson is registered for the Boston Marathon on Monday and said she will start if her body cooperates on Sunday. After Boston, her calendar is already busy. She plans to run Badwater again in late July and wants to go after the overall course record. She is also signed up for the Triple Crown of 200s, which includes the Tahoe 200, Bigfoot 200, and Moab 240, with an eye on lowering the cumulative time record for the three events.
She does not count weekly mileage. Instead, she logs 15 to 18 hours of running each week, split between outdoor runs and her beloved treadmill, along with time on the bike.
