Kylie Jenner shows off her rock-hard abs in saucy Instagram video

Despite the fact there's been a lot of debate over whether or not Kylie Jenner has had any cosmetic surgeries, her body is the envy of millions of people around the world. A feat made more impressive by the fact that the 21-year-old makeup mogul is a mother to one-year-old Stormi.

Now, a little over a year on from the most talked-about hidden pregnancy of the century so far, the recently declared "Youngest Self-Made Billionaire" has been showing off her rock-hard abs on Instagram.

This how well Kylie's body has bounced back after pregnancy: 

Kylie wrote over the video, which she posted on her Instagram story, "I'm proud of my little stomach."

And to be fair, she has reason to be. Apparently the mom-of-one wasn't much of a gym goer (unlike her sisters), but after giving birth to Stormi last February, she hit the gym in a mission to get her pre-baby bod back.

"Kylie has never been a fan of working out in the past," a source revealed in an interview with E! News. "But has recently started a new routine and has been trying to be very consistent."

This routine consists of high-intensity interval training (HIIT) She "needs to be constantly switching up the moves," the source explained. She's also doing "a lot of weights, cardio, running, squats, and pushups."

Another source revealed that while she wasn't a gym bunny like her sisters, they've helped motivate her to get in shape.

And even though Kylie's busy working on herself, she's still got plenty of time for Stormi.

She recently posted this video to Instagram of the one-year-old doing her makeup - and Stormi says "momma"! 

Who needs Jordyn Woods when you have your very own mini-me, eh?!