It's a cinch! Kourtney Kardashian shows off trim figure as she wears waist-trainer after skipping the gym to spend day with kids

Her sisters Kim and Khloe Kardashian swear by it.

And now Kourtney Kardashian, 36, is following in their footsteps, taking up the waist-cinching fad and showing off her trim figure as she cleaned out her closet.

The reality star and mother-of-three posted a selfie while wearing the black-and-blue trainer to Instagram on Saturday, telling fans she was 'obsessed' with the corset-like contraption.

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'Obsessed': Kourtney Kardashian  wore a waist-trainer in a selfie she shared with fans on Instagram on Saturday

'Obsessed': Kourtney Kardashian wore a waist-trainer in a selfie she shared with fans on Instagram on Saturday

Kourtney, who gave birth to her third child, son Reign on December 14, paired the bright waist trainer with black leggings and a black halter-neck top.

'I am pretty much the queen of multitasking,' she captioned the picture.

'Obsessed with anything where I am doing more than one thing at a time, especially since I skipped the gym today.'

'A little Saturday morning waist cinching and working on my posture while cleaning out my closet. Thank you @premadonna87 @waistgangsociety for my obsession!!!'

And on Sunday, Kourtney showed off her new sneakers, courtesy of brother-in-law Kanye West.

Kicking back: Kourtney showed off her new Yeezy Boost 350 sneakers, designed by her brother-in-law Kanye West

Kicking back: Kourtney showed off her new Yeezy Boost 350 sneakers, designed by her brother-in-law Kanye West

The reality star posted a photo of her dark Yeezy Boost 350s resting on the dashboard.

'Finally made my size!!' she wrote beside the photo of the highly-coveted Adidas shoes designed by the rapper.

Fans of the waist trainer say it helps women obtain an hourglass figure and bounce back to their pre-pregnancy shape.

Her sisters Kim Kardashian West, 34, and Khloe Kardashian are also devoted fans of the waist-trainer, sharing selfies of themselves with fans on Instagram. 

Family fad: Kim Kardashian West also was a fan of the corset-like device, which users say creates an hourglass figure

Family fad: Kim Kardashian West also was a fan of the corset-like device, which users say creates an hourglass figure

Kim shared a throwback Thursday selfie while wearing a black corset which showed off her famous curves.

Sister Khloe, who lost 30lbs after discovering a passion for working out after her split from ex-husband Lamar Odom, also showed off her fit figure in a black waist trainer earlier this week.

'I'm obsessed with the gym but a little extra help never hurt nobody,' the 31-year-old wrote.

Breath in: Khloe Kardashian shows off her impressive weight loss

Breath in: Khloe Kardashian shows off her impressive weight loss

Kourtney is also adjusting to life as a single mom after splitting from long term partner Scott Disick after he was photographed partying with an ex-girlfriend in Europe in July.

In addition to baby Reign, the estranged pair are parents to to three-year-old Penelope and five-year-old son Mason. 

Earlier on Saturday, Kourtney took Mason and Penelope to a farmer's market, before taking the kids out to lunch in Malibu.

Single mom: Kourtney and a female friend take her kids Mason, Penelope and Reign to a farmer's market on Saturday

Single mom: Kourtney and a female friend take her kids Mason, Penelope and Reign to a farmer's market on Saturday

Make a mesh of it in Kourtney's bomber jacket by Nike

Kourtney Kardashian always mesh-merizes us with her on fleek daytime style.

The reality TV star always manages to look impeccable despite being a mother to three children, and she’s by no means behind her fashionable sisters when it comes to trends.

Here, Kourtney caught our eye as she pushed baby Reign in a pram wearing a black mesh bomber jacket by Nike. Now that’s one cool mumma!

The sports luxe jacket is designed in a mesh texture for ultimate breath-ability, whilst the partially lined shoulders and chest retain body heat and provide ventilation – plus, it looks really great. Yep, we said it, we're all about aesthetics...

We particularly love the ombre multi colored zip detail, and we've decided it needs to belong in our wardrobe. So the good news is that it's available to buy online; just click through to the right to snap it up now from Urban Outfitters for $110.

If you fancy a window shop first, head to the edit below to snap up our top alternatives from the likes of Stella McCartney to Boohoo.

* PRICES MAY NOT BE AS ADVERTISED

During their outing, the family were joined by female friend as they visited a farmer's market in the morning.

Looking serious, Kourtney wore black leggings and a zip-up workout jacket, and shielded her eyes with large sunglasses.

She got a hand from son Mason, who helped her push his little brother Reign in the stroller.

Helping hand: Mason helps his mom push baby brother Reign's stroller

Helping hand: Mason helps his mom push baby brother Reign's stroller

Later, the busy mom took Mason and Penelope with her to lunch in Malibu.

There, protective Kourtney held their hands as they walked across the parking lot.

The Keeping Up With The Kardashians star had ditched her workout gear, and instead showed off her toned legs in tripped Daisy Dukes and cute ankle boots.

She and Penelope wore matching reflective sunglasses, while Mason looked cute in a stripped tank and red shoes as he held a mini iPad.

The family were later seen enjoying some of the rides at the carnival in Malibu. 

New look: Kourtney changed into Daisy Duke cut-offs as she headed to lunch in Malibu with the children

New look: Kourtney changed into Daisy Duke cut-offs as she headed to lunch in Malibu with the children

Mother-daughter style: Penelope and Kourtney wore matching reflective sunglasses as they stepped out in Malibu

Mother-daughter style: Penelope and Kourtney wore matching reflective sunglasses as they stepped out in Malibu

Fun at the fair: Kourtney took her two eldest kids to the carnival in Malibu 

Fun at the fair: Kourtney took her two eldest kids to the carnival in Malibu 

Riding around: Mason and Penelope seemed to have a great time going round and round on the carousel horses as their mom kept a watchful eye on them

Riding around: Mason and Penelope seemed to have a great time going round and round on the carousel horses as their mom kept a watchful eye on them

 

 

 

 

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