Since getting the go ahead from her doctors to resume workouts with her personal trainer earlier this month, the 33-year-old Keeping Up With the Kardashians star — who has been living in Cleveland alongside her boyfriend, Cavaliers player Tristan Thompson — has prioritized fitting workouts into her daily routine, even though it’s caused her to feel incredibly sore.
While the new mom commented on Monday that getting back into her old fitness routine is “much more difficult than I think you’d expect it to be,” she added that it also felt “really good.”
Following her older sister’s lead, the Kylie Cosmetics mogul, 20, also celebrated Sunday by sharing a photo of her bare stomach on Instagram.
A source previously told PEOPLE that since giving birth, the 20-year-old has been “super determined to 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.”
The youngest KarJenner sibling previously shared that she still has some post-baby weight to lose after giving birth to Stormi. “I need to lose 20 lbs. but this just looks too good!” she said in a Snapchat video in April that showed someone serving her a tray of oven-fresh rolls.
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.
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Earlier this week, Kardashian defended her dedication to fitness after 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.
“Just because I have a baby doesn’t mean I have to stop doing the things that I love, and I love working out and getting my mind right,” she added.
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.”