Kardashian — whogave birth to her daughterTrue Thompsonsix weeks ago on April 12 — proudly lifted up her shirt on Sunday morning to show off her toned tummy on her Instagram Story.

Since getting the go ahead from her doctors toresume workouts with her personal trainerearlier this month, the 33-year-oldKeeping Up With the Kardashiansstar — who has been living in Cleveland alongside her boyfriend, Cavaliers playerTristan Thompson— has prioritized fitting workouts into her daily routine, even though it’s caused her to feelincredibly sore.

While the new mom commented on Monday that getting back into her old fitness routine is “much more difficultthan I think you’d expect it to be,” she added that it also felt “really good.”

Khloe Kardashian/Instagram

khloe-kardash

Clad in a black spaghetti strap top and a form-fitting pair of jeans, Jenner, who welcomed her first daughterStormion Feb. 1,showed off her fit figure.

A source previously told PEOPLE that since giving birth, the 20-year-old has been “super determinedto get back to her pre-pregnancy body.”

“Kylie wants to be a really hot young mom and is making sure that happens,” the insider continued, adding that as Jenner gets further along in her transformation, she will be “flaunting her progress more and more.”

Also in March, Jenner revealed that she gained a total of 40 lbs. during pregnancy in a now-deleted tweet during a Q&A session with fans and followers.

Earlier this week, Kardashiandefended her dedication to fitnessafter getting some criticism that she was spending too much time away from her newborn daughter.

“What I’m annoyed about is that I’ve read a couple of times on Twitter that, you know, they feel that I’m focusing too much on my body, but the truth is, I’ve worked out five or six days a week before I got pregnant and that’s my sanctuary and something I love to do,” Kardashian said.

Kardashian has said she’s continuing to work on targeting certain areas, including her backside.

“Muscle memory is a real thing because it’s still under there. Got to tighten it all up,” she remarked last week. “I’ve got to get rid of this part. Just need everything to be solid.”

source: people.com