Hilary Duff baby studio city singer blonde

All those daily Pilates sessions are sure paying off!

Hilary Duff took her adorable son Luca to a Mommy-And-Me class today in Studio City, and the singer/actress decided to show off her amazingly toned arms in a sleeveless green blouse, which she paired with skinny jeans that showed off her equally slender stems!

She might be back to her pre-baby bod, but the Lizzie Maguire star insists it wasn't as easy at it looked!

"I'm finally at a comfortable place with my body. It took me a full year," she recently told Life & Style.

We think she looks more fit than ever! You go Hil!