Chontel Duncan doesn’t have to worry about losing the baby weight! The Australian fitness model showed off her incredible abs just five days after giving birth to her son, Jeremiah.

“My body is tender, it feels like someone did 12 rounds in the boxing ring using my core as the target,” the new mom wrote on Thursday, March 31, alongside an Instagram photo of herself in a neon orange bikini. “I can’t believe my bump is gone & I no longer have my baby hiding inside of me.”

The former Miss Universe finalist continued: “I wonder because I can’t get back into training for a longer period of time how my body will change through purely just recovery/rest and nutrition.”

Duncan, 27, and her husband, Sam, welcomed their 7-pound, 13-ounce baby on March 25.

“Healthy happy baby boy, absolutely nothing medically wrong with bubba, he is extremely alert and very strong shocking the staff here with his arms and neck strength,” Duncan announced on Instagram March 26. “Absolute champion on the boob & feeding very regularly no problem.”

No one will ever hurt you Miah 😚 @sam_hiitaustralia

A video posted by 🇦🇺🇳🇿SnapChat👉🏽 ChontelDuncan (@chontelduncan) on

The 6-foot-1 social media sensation first grabbed headlines in November after posing tummy-to-tummy with her friend Nat, who was four weeks further along in her pregnancy.

Addressing the difference in their belly sizes, Duncan noted: “Each woman carries differently, and this most certainly doesn’t mean one is doing something wrong or not healthy. We both have healthy growing babies, and we both have had incredible pregnancies so far, feeling amazing and full of energy.”

Duncan, who works as a trainer at Hiit gym, was still kickboxing and doing plate pushes at 37 weeks pregnant.

In a March 15 interview, Duncan revealed to Us Weekly that she had only gained 24 pounds up to that point in her pregnancy. “People think I’m harming my baby … and that I’m all about staying skinny and not nourishing my little D,” she told Us. “I know it’s hard to believe that someone can carry a child the way I am, but in reality, a lot of women carry like me.”