While we've gotten sneak peeks at Carrie Underwood via her Instagram since she gave birth to son Isaiah Michael about three months ago, she made her big post-baby debut on Tuesday at the Grand Ole Opry ahead of the CMT Awards. Donning a short body-hugging blue dress, the country singer looked incredible as she performed on stage – and posed backstage with Arnold Schwarzenegger and Tom Arnold.

Carrie kicked off CMA Music Festival week with a performance at the Grand Ole Opry Photo: Chris Hollo

"That moment when you feel like Jamie Lee Curtis #TrueLies," she captioned her Instagram pic with the Hollywood stars. "It was so wonderful meeting Arnold Schwarzenegger and Tom Arnold tonight at the Opry!"

Clearly excited for her appearance at the CMT Awards, the 32-year-old also posted a glimpse of her rehearsal hours earlier saying, "Rehearsal for the #CMT Awards I can't wait!"

How did she get in such good shape in just a few months? "We do lots of lunges, squats, plyometrics, stairs, pull-ups along with weight training. The key to the success is keeping all of this at your level and not to do too much too soon. Listen to your body," Carrie's trainer Erin Oprea told E! News following the singer's recent photo shoot for her new fall line of CALIA fitness lifestyle apparel. "Core exercises are great to help tone the body, but a slimmer midsection is truly made in the kitchen. Eating clean is the fastest way to get flatter."

Rehearsals for the #CMTAwards I can't wait!

A photo posted by Carrie Underwood (@carrieunderwood) on

Erin added that nap time for the baby is mom time for Carrie, which was clearly evident in a new picture the blonde beauty shared showing her young son and husband Mike Fisher sound asleep during her rehearsal. Isaiah's first band rehearsal," she captioned the adorable snap. "As you can see he & his daddy were totally into it!#naptime #earmuffs#sweetdreams."

Isaiah's first band rehearsal...as you can see he & his daddy were totally into it! #naptime #earmuffs #sweetdreams

A photo posted by Carrie Underwood (@carrieunderwood) on

Carrie's hard work has paid off as she is nominated for five CMT Awards that airs live from Nashville on June 10 at 8 p.m. ET.

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