Broadway star Kelli O’Hara is currently gearing up for her next big performance: The 50th TCS New York City Marathon. The Tony winner, who has also received Emmy and Grammy nominations for her work, will hit the NYC streets to raise money for the Cancer Support Community this weekend. “This has been an extraordinary test of what it means to stick it out,” O’Hara tells SELF. “There were days when I thought, Could I do this? But for the most part, I thought, No—this is what I want to do.”

O’Hara most recently racked up awards for her starring role as Anna Loenowens in The King and I, which she performed on Broadway, on London’s West End, and in Tokyo’s Orb Theatre. She’s also starred in Kiss Me, Kate; South Pacific; and The Bridges of Madison County, among several other shows nationwide.

Though O’Hara has long considered herself a runner, this will be her first marathon. “I started running when I was 12 or 13 years old, just getting out and running in a way that felt like therapy, where I could think things out,” she says. Running continued to be an outlet for O’Hara as her career in show business took off. “When I was in my 20s, I would run Central Park all the time, or Riverside Park. That was always my form of exercise and relaxation. But it was more like six miles—it was never 26.2.”

There’s a nostalgic element to the marathon for O’Hara too. After all, the city’s tentpole community sport event is one of its most lovable traditions, up there right next to Broadway. “I lived in New York forever, and I would always see the marathon going by on my way to the matinee,” she says. “And I’d always be like, I don’t have time to train for that because I’m doing eight shows a week and I’m exhausted already.” This past year, however, the timing finally felt right.

“I really do feel good about it.” she tells SELF. “I know it’s going to be hard. I’m not 20 anymore, but for that reason especially, I feel like I have a little more benefit in having a bit of wisdom when it comes to longevity.” Below, O’Hara tells SELF about the running favorites she’ll be using on race day.