Emily Sisson ran 1:06:52 to break her own American record by 19 seconds en route to finishing second place overall at the Houston Half Marathon on Sunday morning. She is the first U.S. woman to run under 67 minutes on a record-eligible course, and she owns four of the top six all-time fastest marks in the distance by an American woman.

The 31-year-old from Flagstaff, Arizona, opens 2023 with a bang after a record-setting 2022 that saw her set American records in the half marathon (1:07:11) last spring, and the full marathon (2:18:29) at the Chicago Marathon. In doing so, she became the first American woman to hold both national records since Deena Kastor held both marks from 2006-2018

She averaged 5:07 per mile in the record run, though her pace slowed slightly after a quick opening 5K of 15:31. Hiwot Gebremaryam of Ethiopia took the race out hot, splitting 15:14 (4:54 pace) for the first 5K, and held on to win in 1:06:28. Sisson made up some ground on Gebremaryam, but wondered after the race if she could have run faster with a more even effort.

“I think I could have run a little more evenly so I’m hoping to run another half and run even faster,” Sisson told ABC-13 in Houston. “I wanted to try and go for the win but [Gebremaryam] was just too good today. My main focus was on competing and hoping the time was fast at the end of the day. I went a little too fast the first few miles so the last few miles I was definitely feeling it.”

Sisson raced in the brand-new New Balance FuelCell SuperComp Pacer.

Her long-time training partner Molly Huddle finished as fifth overall and second American in 1:10:01, nine months after giving birth to her daughter, Josephine. Huddle, who had set a new American record with a 1:07:25 on the same course in 2018, cut three and a half minutes from her last half marathon outing this past fall.

American Women Racing in Houston

Several other high-profile American women also made their debuts in the distance. Former 1,500m specialist and 2011 world champion Jenny Simpson took her first crack at 13.1 miles, and finished as the fifth American in 1:10:35. Vanessa Fraser of the Nike Bowerman Track Club, who has run one of the fastest-ever U.S. indoor 5Ks in 14:48, made her debut in 1:11:00 as the ninth American. Both women qualified for the 2024 U.S. Olympic Trials Marathon by running faster than 1:12.

According to Fast Women, a total of eight women qualified for the U.S. Olympic Trials for the first time by either running under 1:12 for the half, or 2:37 for the full: Huddle (1:10:01), Erika Kemp (1:10:14), Simpson (1:10:35), Amy Davis-Green (1:10:58), Fraser (1:11:00), Elena Hayday (1:11:33), Jacqueline Gaughan (2:34:26) and Jennifer Pope (2:36:24). Kemp was seventh overall, while another American Lindsay Flanagan was eighth overall (1:10:20), but she had already qualified for the U.S. Olympic Trials.