Jessica Simpson's Surprising Secret For Staying Fit During Lockdown Is Revealed

Jessica Simpson has a simple secret for staying in shape during lockdown, and it only involves one piece of gym equipment -- or a check-in with Mother Nature.

After the 39-year-old mom of three shared a photo of her fit physique following an early morning workout, an insider gave the skinny on how the star stays committed to her fitness and diet routine while quarantining at home in California with her husband and kids.

An insider told Entertainment Tonight that Jessica has primarily been walking to keep her body toned, also taking strolls as a way to clear her head amid the coronavirus pandemic.

"She is walking outdoors and on her treadmill... It's the way she stays sane, so it's as much for mental health as it is for physical wellness."

Indeed, in the caption attached to her workout photo, Jessica noted that she got her "steps" in for the day. One look at her muscular legs made it clear that she's been getting her steps in on a regular basis.

The insider also revealed that Jessica is practicing moderation when it comes to her diet.

Fans of the singer and fashion designer's social media pages know that she has been spending a lot of time in the kitchen while at home due to the health pandemic. In recent weeks, Jessica has shared photos of her making a huge pot of chili, a seven-layer taco dip, and baking a sweet treat with her 8-year-old daughter, Maxwell. The source noted that the baking, in particular, has become a regular thing in Jessica's house.

"There has definitely been a lot of baking going on with the kids and she doesn't totally deny herself," the insider said, adding that Jessica simply practices portion control when she enjoys a treat with her family.

Jessica -- who shares Maxwell Drew, 8, Ace Knute, 6, and Birdie Mae, 1, with her husband Eric Johnson -- has been vocal about the fact that she gained 100 pounds while pregnant with her baby last year, and weighed 240 pounds before giving birth. After Birdie was born, Jessica jumped right into a fitness regimen and lost her pregnancy weight within six months.

Jessica's longtime trainer, Harley Pasternak, told E! News said the Open Book author started out by walking 6,000 steps per day, and has now worked her way up to 14,000. The star also focuses on eating three protein-packed meals a day and healthy snacks such as almonds. Jessica also allows herself "cheat meals" throughout the week, when she eats whatever she wants in moderation -- which explains all that baking and chili-making in her house.