The reality TV - who recently lost weight but has still managed to retain her stunning curves - enjoys undergoing regular exercise but will only do it if she knows she looks good.
Speaking at the launch of work-out apparel brand Bravada International, Kim told People magazine: "The line is something that I've aligned myself with because it's something that I wear all the time.
"I mean, it's really hard for me to find fitness clothes and the sports bras sometimes don't fit, or the pants are all different sizes - this line is all only one size and it really does fit all my sisters and they're all different sizes. It's so stretchy, and it's stylish. You wanna look good when you go to the gym. You wanna feel your best."
Kim, 29, credits her svelte body with being "tortured" at a boot camp.
She said: "I'm kind of loving Barry's Bootcamp. It's torture but it's amazing. I see a difference right away when I go."
