Watch Chelsea Handler Do the 'Hardest Plank Variation'

Just looking at this move will make your abs hurt.

Chelsea Handler is leveling up her core work.

The actress recently shared a video on Instagram of her doing a challenging exercise with longtime trainer Ben Bruno.

"@chelseahandler has got way more than 99 problems, but her core strength ain’t one," writes Bruno in the caption of his post. "Really impressive stuff here — a lot of pro athletes struggle with this one."

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In the clip, Handler is wearing a long-sleeve white t-shirt, black leggings, and Nike sneakers. She's in a forearm plank position with her elbows resting on a pad and her toes on top of a slider. The comedian also has a weight plate balanced on her back, and Bruno is holding a long resistance band looped around her ankles. She completes a few body saw reps, subtly shifting her weight forward and back while maintaining the plank position.

"This might be the hardest plank variation we've ever done," says Bruno in a voiceover playing along with the video. "I don't like being too nice to Chelsea, but her core strength is really impressive. She can do a plank for 10 minutes, no problem, so regular planks just ain't gonna cut it," he continues. (Read More: How Long Do You Really Need to Hold a Plank?)

Planks alone are a solid abs exercise, so this variation really speaks to Handler's overall strength. "Planks are great for core stabilization; they also work the quads, glutes, low back muscles, traps, lats, pecs, biceps, and triceps," Taylor Rae, certified functional strength coach and trainer at Fiture, tells Shape.

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In order to up the ante, Bruno has thrown in three obstacles for Handler: adding movement, a plate on her back, and a resistance band around her feet. "I'm actually pulling really hard [on the resistance band] because I found that the harder I pull the less she talks," jokes Bruno in the clip.

"With the added challenges of the band, the weight, and transforming this from an isometric hold — [such as] a standard plank — to a body saw, [you] have added stress on the entire body, especially the abs and obliques," explains Rae, who watched the video of Handler doing this challenging move.

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"Fundamental movements with added resistance and time are the best, safest, and most reliable way to build strength and endurance," adds Rae. However, this exercise isn't exactly for beginners. "While this movement is exciting, it can be risky, and I recommend it only be done by experienced gym-goers and athletes under the supervision of a certified fitness professional," says Rae.

If you're looking for a way to spice up your plank exercises without adding too much risk, you can start with a body saw using just your bodyweight for a longer interval of time, advises Rae.