Finishing a marathon is an impressive feat no matter how fast you run it. But despite the difficulty of the distance alone, Cynthia Arnold upped the ante when she decided to run the Missoula, Montana marathon while pushing her three children, aged 6, 4, and 1, in a triple baby stroller. What’s more, the 35-year-old mom unofficially broke a Guinness World Record in the process, according to Runner’s World.

Arnold had already set the Guinness World Record for “fastest half-marathon pushing a triple pram (female)” back in July 2018 with a time of 1 hour, 29 minutes, and 8 seconds, so it’s only natural that she went for the full marathon record this past June. The time to beat was 4:06:33, set by Ann Marie Cody in March 2018, but Arnold didn’t settle for scraping by. She finished the marathon in 3 hours and 11 minutes, keeping an average pace of less than 7 minutes and 20 seconds per mile.

Arnold started training for the Missoula marathon over the winter, mostly without her children in tow. She kept her runs with the kids limited to around 10 miles, she told Runner’s World. The weight of her three kids combined is about 130 pounds, and the total weight factoring in the stroller is around 185 pounds. Unsurprisingly, her kids seem to have a blast while they hitch a ride with mom.

The feat had to be recorded so Guinness could verify it, and some adorable clips came from the footage Arnold captured on the run.

“Running alone in a race is so simple now,” Arnold told Runner’s World. “It’s interesting to me how my perspective has changed as I have grown as a mother. I used to really stress so much about racing, and now it’s sort of the last thing I’m thinking about.”

Now that she’s broken the record she set out to break, Arnold is planning on running a marathon solo soon. Her latest record hasn’t been officially acknowledged by Guinness yet, but keep an eye out for it.