Kim Zolciak showed off her growing baby bump on Instagram on Saturday, July 27. Credit: kimzolciakbiermann/ Instagram

Mamma mia! Kim Zolciak shared a snapshot of her growing baby bump with fans via Instagram on Saturday, July 27, and proved that even with a bun in the oven, she can still work up a sweat at the gym.

"You asked for it … here is my baby bump this morning!" the Real Housewives of Atlanta captioned the photo, in which she poses with one hand protectively cradling her pregnant belly. In the photo, Zolciak, 35, wears a sports bra and sweat pants, with her blonde hair piled high on her head.

This is the fifth child for the reality star, who is already mom to daughters Brielle, 16, and Ariana, 12, from a previous relationship, as well as son Kroy, Jr., 2, with husband Kroy Biermann. Biermann, 27, recently adopted Zolciak's two daughters.

"I don't know if I could love anybody else's children as much as Kroy loves the girls," Zolciak said during an interview with E! News. "I just don't know if I have it in me."

"Kim loves being pregnant," a source told Us in June. "She really wants a little girl."

Added the source, "Brielle and Ariana are older now, and Kroy wants a girl of his own."