How do you make a government shutdown even more stressful? If you’re Rep. Kyrsten Sinema, you were training for a 140.6-mile endurance race.

The Arizona Democrat found herself in a particularly unusual bind last month. Not only was she on track to become the first serving member of Congress to compete in an Ironman Triathlon (Sunday in Tempe), but she also was dealing with the shutdown stress, which meant she was craving sugary comfort foods. Luckily, her coach had some advice.

“He said, ‘If you’re going to eat sugar, eat sugar high in fat, because you’ll be satiated faster,’ ” Sinema told us last week, shortly after her daily workout. “I was like, ‘So you’re telling me to go have a cupcake? I can do that.’ ”

An Ironman competition — 2.4 mile-swim, 112-mile bike ride, 26.2-mile run, all completed within 17 hours — brings a singular set of difficulties when you’re in Congress: constant travel and packed schedules in addition to many hours of training. But Sinema, 37, shrugged it off — everyone has challenges. And she found a way to fit it all in.

“I just wake up at 3 a.m. most days,” the first-term congresswoman said matter-of-factly. That meant going to bed early, even when there are evening parties to attend. “Like around 8 p.m., I’ll be at an event and I’ll look around and start to panic a little bit because I’m thinking, ‘I have to go home and eat and go to bed.’ ” It was also tough flying back and forth between her home district and Washington — but really, it’s all about discipline, she said.

Sinema, a marathon runner, decided to take on the Ironman because it was something she thought she could never do. She volunteered in last year’s race, therefore securing herself a spot this year. The race features competitors from all over the world and sold out in a nanosecond. Oh, and there was one other little problem: She couldn’t swim and was terrified of open water — the swimming portion of the Arizona Ironman, in her district, takes place in the Tempe Town Lake.

So she hired former Olympic swimmer (and her neighbor) Misty Hyman to be her swim coach. In between congressional duties, she trained, whether doing hundreds of miles on her bike in Arizona, or running loops around the Mall in the District.

Aside from the personal challenge, she also raced to raise money for the Desert States Charitable Foundation, an Arizona-based charity that gives college scholarships to low-income kids — an issue close to the congresswoman, who was homeless as a child and went to college on scholarships.

Sinema’s final time in Sunday’s race: 15 hours, 12 minutes and 34 seconds. And wasn’t she jazzed about becoming the first member of Congress to compete in the grueling competition?

“No,” she said. “I mean, I’m the first in a lot of things, but I don’t care much about that. . . . I just want to finish the race and feel good.”