While talking to E! News' Sibley Scoles on the set of her upcoming E! show Revenge Body With Khloe Kardashian, the 31-year-old shared that her engaged brother is "really committed" when it comes to getting fit.
"All of us are like really athletic and competitive, so we're all really good," Khloe explains when describing what it's like to workout with her family members. "Rob is—I don't work out with Rob—but Rob is like, he's really committed when he's in there, he's like really serious about it. We're all pretty serious about it."
As for who her favorite workout partner is? Well, it turned out to be someone she didn't expect—Kourtney Kardashian.
"I was always like really resistant to working out with her, because I was like 'She's going to be such a baby,' and I am way too aggressive and she keeps up with me. Kim Kardashian and I can't work out together...Because she's a little...She like kind of walks, and I want to run."
Like we said—beast mode.
Khloe also spoke to E! News about life as an auntie and the possibility of having her own kids in the future. Watch the clip above to see what she had to tell us.