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How exactly does Kate Hudson get her rock-hard abs?

Through hard work -- and a little play.

The actress showed fans how to have a little fun while toning up in a new Instagram video she shared on Nov. 14.

In the lighthearted clip, the 36-year-old mother of two throws punches and does burpees with the help of MMA fighter James "The Beast" Wilson -- then laughs and does a goofy dance to distract when she can't keep up with the professional athlete's punishing pace.

"I'm pretty sure I could take him....🤓 @james_thebeastwilson #MMA#TheBeast #KickBoxing," she wrote alongside her video post.

James also shared a photo of himself with Kate and joked that he was "getting my a-- kicked" by the actress during their rooftop photo shoot and sweat session.

"I've been doing Pilates for so many years, my main workout is always focused on the core," Kate told Glamour in June 2015 of how she stays in such great shape. "It's mainly core. When everything starts from the core, I think that's where the strength comes from and that should be the center of everything."

Kate wears workout attire from her Fabletics clothing line in the clip with James.