Kim Kardashian Instagrams a fitness selfie on July 19. Credit: Courtesy of Kim Kardashian

Keeping Up With Kim Kardashian's Workout! The newlywed mother, 33, is determined to stay in shape, and takes advantage of any free time she may have. 

"Gym time while my baby is napping!" Kardashian captioned a gym selfie on Instagram on July 19. 

The mother of 12-month-old daughter North wore a black sports bra and leggings with Nike sneakers. She slicked her long brunette locks back in a ponytail, posing next to a treadmill. 

The reality star recently hit more than 16 million Instagram followers, prompting her to post several bikini shots of her toned body.

"#NoFlexZone," she captioned one full-body image.