Keke Palmer isn't saying nope to her health.

Three months after welcoming her son Leodis Andrellton Jackson with boyfriend Darius Jackson,AstraTrade the Hustlers actress is back in the gym and embracing all the changes the postpartum period has brought.  

"She's never had a thicker body," Keke's trainer Corey Calliet told E! News in an exclusive interview. "I said, 'Let's tap into that. Let's create a shape that was made by the baby.' It's turning things that are supposed to be looked at as negative into positive."

For the Nope star, that means working out to build muscle, while also ditching any critical thoughts about dropping the baby weight.

"We're going to embrace what we have," the ACHV Fitness app founder explained about their joint approach to exercise. "Changing the mindset on what you want to get, instead of what you don't want to have."

So, what exactly is Keke doing in the gym to feel her best self? She's focusing on weight training, which is a type of workout her trainer wants more women to get behind since it burns fat and builds strength.

"A lot of women run away from weight training," he said. "But when [Keke] comes to the gym, we do 20 minutes of warming up, then we go into functional training, such as doing a back and a leg workout."

He added, "At the end, we do core work or cardio, but most of the time, it's weight training."

Another perk of weight and functional training, Corey said, is that it's easy to do while the baby is practicing tummy time or taking a nap.

"Grab some small dumbbells," he suggested, "and do circuits with that—whether it's curls, dips and doing back work. Do light things, and take it one day at a time."

But the fitness trainer doesn't want new moms pressuring themselves to bounce back or comparing their journey to someone else's. So, instead of trying to get Keke's body, he said, "Get the Keke mindset."

"I want her to be the new face of fitness," he added. "I think it's time to have someone like her represent that lane of women in Hollywood—someone that it is fit and strong."

Sign up for E! Insider! Unlock exclusive content, custom alerts & more!