The 'Sin City' actress has revealed her secret to staying fit is to keep her children - Honor, six, and Haven, three - entertained by running around with them.
Talking to Glamour magazine, Jessica said: "Running around after two little girls has become a permanent hobby which helps me to stay in shape: with my hectic schedule every little helps!"
Along with messing around with her girls, the starlet admitted that she uses exercise as a way to de-stress and enjoys a varied routine to keep her interested in the gym. She said: "[It's] hugely important to me - it is the foundation of any body care routine since it relieves the stress that often shows up on your body in other ways. I make sure to mix it up with yoga, hip hop dance and running to keep me interested."
The 33-year-old beauty also explained that she maintains her flawless skin with a structured cleansing at the end of every day. She told Glamour: "I like to maintain a good beauty regime using the best products, with my skin being the most important. I like to keep to a routine as much as possible - so that even when my schedule is crazy there are always some elements that help me maintain looking and feeling good."