Sarah Stage is heading back to her pilates work-out one month after giving birth to her first child.

See Sarah Stage's Post-Baby Bod Four Days After Giving Birth

The model, who became a massive sensation with her tiny pregnant belly, posted a new photo on Instagram that shows off her athletic torso. It appears that having a baby didn't change her muscular figure at all since she still has abs and strong legs.

She wrote in the picture's caption, "First day back at @carriespilatesplus since James was born. feels good to slowly get back into it."

 First day back at @carriespilatesplus since James was born feels good to slowly get back into it

A photo posted by SARAH STAGE (@sarahstage) on May 27, 2015 at 2:15pm PDT

Fans Gush Over Sarah Stage's Baby In Instagram Pic

Ever since the model gave birth to baby James, she's posted images of her son all over the place. In the most recent shot, the child lies down on his mommy's lap and stares into the camera with his mesmerizing eyes. He wears a onesie that has Darth Vader from Star Wars- or in this case- 'Barf Vader.'

 Barf Vader.

A photo posted by SARAH STAGE (@sarahstage) on May 25, 2015 at 7:17pm PDT

Fans commented on this photo on how adorable James is; one user wrote, "He is perfection!" while another complimented the model and threw all negative messages aside: "Oh Sarah he's gorgeous! ! It's funny how thru out your pregnancy u got so much hate mail. Saying you were unhealthy and now look at James born healthy as a peach pie. How can u sleep @sarahstage I would be kissing him and cuddling him all night lol. So happy for you."

James was born on April 14, 2015.

Tags: Sarah Stage