Blake Lively welcomed her first child in December 2014 and snapped back into a bikini just two months later to shoot her shark thriller The Shallows. Now, she’s back at it again: Having given birth to daughter Ines in September 2016, next up the mom of two will get in fighting shape for the upcoming film Bruised about a single mother who does cage fighting.

So how on earth does Lively manage to drop the pounds so quickly? While it’s hard for us to relate to the pressure of having to film a movie months after giving birth, her surprising tip for shedding the pounds is something we could all learn from. Instead of focusing on cardio, the actress maintains her figure with a strict strength-training regime.

Both Lively and her husband Ryan Reynolds work with Don Saladino of Drive Gym, and the trainer has the power couple working it with the weights. “When you are doing those exercises, you are not training one area of the body. They are complex and compound and they are requiring the whole body to work. You also get that cardiovascular effect too,” he told Health of the strength-training circuits he does with Lively.

Some examples of the full-body moves that get the actress in top shape are farmer’s walks, sled pushes, squats, deadlifts, and incline pushups. “This is burning high calories, and getting her foundation really, really strong,” he added.

In fact, when Lively was training for The Shallows, she bumped up her workouts from one or two times a week to five or six, and most of those sessions were focused on weights, not cardio. “We would do an upper body workout Monday, lower body Tuesday. Wednesday was a playful pool workout where she would do laps,” Saladino told People. “Thursday was upper body, Friday lower body, and Saturday we were focusing on the accessory movers: the arms, the shoulders.”

While that sounds like a ton of time in the gym, Saladino promises that you don’t need a full hour each day to get results. “You can get in and do things in 20-30 minutes, and you could build a world-class physique in that time that moves the right way,” he told Health. And when Lively isn’t feeling a full workout, he encourages her to get active in any small way, even if it’s just spending 10 minutes on the elliptical.

“When you feel great, get on it. When you don’t feel great, shift down a gear. And when you feel like complete crap do really minimal work,” he told People.

And workouts are only part of the plan. To maintain her figure, Lively sticked to a mostly gluten- and soy-free diet, eating minimal processed foods. When she was training for The Shallows, she was particularly strict, eating mostly protein, vegetables, and complex carbohydrates. But the actress doesn’t totally deprive herself: She sticks to an 80/20 diet, and allows herself to indulge on “cheat foods” about 20 percent of the time.

That sounds like a plan we can get behind.