Carrie Underwood isn't afraid to get a little sweaty.

The 33-year-old singer took to Instagram to share a selfie from her workout on Thursday, no makeup and all!

WATCH: Carrie Underwood Strips Down to Teeny Bikini During Cabo Vacation With Husband Mike Fisher

"I'm a sweaty mess, but I’m a sweaty mess in an adorable tank! @cailabycarrie #staythepath #nomakeup BeNice #run #KeepingItReal #cardio #love," she wrote, along with her barefaced pic. 

Of course, the "adorable tank" Underwood was sporting was a top from Calia, the line of activewear she launched last year. The new mom hasn’t been shy about touting her own collection on Instagram.

RELATED: Carrie Underwood Shares Adorable Photo of Son Isaiah in His Diaper

As for the secret to her toned physique? It's all about simplicity!

WATCH: Carrie Underwood Shares Rare Photo of Son Isaiah: 'I Don't Deserve Such Sweetness'

"You don't need that much," she told ET in May. "I like free weights and a Bosu, and you're in business. Maybe a medicine ball. I do lots of squats and lunges, and I like to run, I like to run outside if my knee allows me to. But just body weight stuff, push-ups, pull-ups."

"It doesn't have to be complicated," she added.

See more in the video below.