Credit: Keola Media/Dean/

Hilary Duff isn't wasting any time when it comes to toning up her post-baby body!

Almost two weeks since giving birth to baby Luca Cruz -- her and hubby Mike Comrie's first baby together -- on March 20, the Lizzie McGuire star is already back at the gym.

"20 minutes on the elliptical seems like an eternity!!! What the hell…" the 24-year-old first-time mom tweeted Saturday.

PHOTOS: Incredible post-baby bodies

On Thursday, Duff made her post-birth debut in West Hollywood where she treated herself to some pampering at Nine Zero One salon while wearing leopard skinny jeans, platform sandals and a blue blouse.

"Just got my hair did from my girl Riawna Capri, thanks love! I'm feeling fresh! Heading back home to hang with munchkin :)" she posted to her Twitter, post-visit.