Kourtney Kardashian has jumped on the crazy post-baby body bandwagon.

Of course, she’s now racing against the clock to slim down.

She gave birth six weeks ago.

And to ensure she wastes no time getting back her pre-baby body Kourtney, 35, has gotten herself the Kardashian sister’s favourite slimming attire – the waist-trainer.

"Gettin' it right, gettin' it tight...with my waist shaper! #waistgangsociety @premadonna87 @pre_shop.". Image via @koutneykardash Instagram

The oldest Kardashian sister is donning all black to assist her slim look - only 6 weeks out of labour. She captions the image with, "Gettin' it right, gettin' it tight...with my waist shaper! #waistgangsociety."

But the black corset look isn't a new one for the Kardashian family. A few months back Kim, 34 took a selfie of her curvaceous attire with accompanying text saying, "#premadonna87 is my fave!"

"On set using my @premadonna87's waist trainer before I shoot! #premadonna87 is my fave! @pre_shop #waistgangsociety" Image via @kimkardashian Instagram

It seems to be a new trend that the siblings can't get enough of. It's designed to slim the waistline overtime after prolonged use of the corset.

The youngest of the Kardashian clan Khloe, 30 is also a huge fan of the figure hugging contraption. She posted this image (in black sports gear too) 6 days ago.

"Early morning workout in my favorite waist shaper thanks to @premadonna87. My secret weapon to snatching my waist! Get the best waist trainer in the game with @pre_shop #Waistgangsociety #PreMadonna87 #Fitness #Pre_Shop" Image via @khloekardashian Instagram

To nail the look it seems you need a corset over black fitness gear, and a posed selfie to accessorise.

We're not sure if we could pull it off - but hey the Kardashian's are looking ever the curvaceous queens. And Kourtney is looking very healthy for giving birth just six weeks ago - whatever makes her feel good right?

What do you think about the waist trainer?

Here's some more pics of the Kardashian's training their waists to help you decide...

Want more? Try: 

"The first pic of Kourtney Kardashian's little baby boy."

"Kourtney Kardashian, maternity style queen."