November 5, 2017, was the 47th running of the New York City Marathon, a 26.2-mile footrace through the streets of the city’s five boroughs. More than 50,000 runners completed the race. One of them, Justine Galloway, was once a world-record runner. Yesterday, she completed the race in six hours, six minutes, and 51 seconds — that’s about three hours and 40 longer than the pace set by the race’s fastest woman, hardly a world-record mark in typical conditions. But that’s okay — there’s nothing typical about Galloway’s penchant for running.

Galloway set her Guinness-recognized record in 2015, then age 35; the San Diego-based biomedical engineer entered a local half-marathon and finished in a time of two hours, 46 minutes, and six seconds. Relative to the rest of the runners, again, that was nothing special; she finished 10,706th out of 13,706 entrants and took more than twice as long to finish as the winners. But she wasn’t like any of the other racers, as is immediately obvious from the below:

Yes, she’s running backward.

Typically, when people do such things, they’re doing so on a lark or, all too often, to get their name in a record book for something as weird as it is impressive. In Galloway’s case, though, that’s far from the truth. Before entering the San Diego Half, she had previously completed nine marathons running forward. And if it were up to her, she’d probably continue running in others (forward) as well. Unfortunately, her brain and body had other ideas.

In the early 2010s, Galloway’s running became increasingly difficult — something was off, but she wasn’t sure what. It just felt like her left leg wasn’t maintaining her gait as it should. She sought the advice of various doctors, most of whom were stumped. One, however, had seen something like this before. The diagnosis was something called dystonia, which Wikipedia characterizes as “a neurological movement disorder syndrome in which sustained or repetitive muscle contractions result in twisting and repetitive movements or abnormal fixed postures.” In Galloway’s case, it was “runner’s dystonia,” a disorder that caused her legs to fail her if she ran for extended distances. And for a marathon runner, that’s a huge problem.

Working with physical therapists, Galloway found a workaround: running backward. For some reason, she discovered, she’s able to run in reverse without the dystonia appearing. So, she began to train for the San Diego Half, just facing the other way. In her preparation, she told Women’s Running, she, on a lark, “searched for a back-ward running record and found the female Guinness World Records title for the fastest half marathon run backward with a 2:49 time.” That seemed beatable and a new goal was in her sights. When she crossed the finish line in San Diego in 2015, she did so with a world record to her credit.

That record has since been bested, so for the time being, Galloway isn’t in the record books. But that may have changed yesterday, as Guinness lists a world-record holder for the fastest backward marathon by a male, but not for a female. But either way, Galloway’s efforts are doing good. She ran the New York City race to raise money for the Michael J. Fox Foundation for Parkinson’s Research with a goal of raising $3,200. (Her father was afflicted by the disease.) As of November 6, 2017, she beat that goal as well — she’s raised more than $5,000.