So this is her secret to getting her pre-pregnancy body back!

Hilary Duff shows off her impressive bending skills in a new Twitter pic, and the blonde beauty sure seems to be taking her Pilates classes seriously!

"Nice stretch... Mmm," she captioned the snapshot, in which she works on her flexibility with her instructor.

The Duffster, who gave birth to son Luca last March, has approached post-pregnancy weight loss the healthy way, and all her hard work is now paying off! The 25-year-old recently tweeted that she's back in her size 26 skinny jeans!

Lookin' leggy Hil!