Lupita Nyong'o Posts Video Undergoing Intense Training to Swim in 'Wakanda Forever': Watch

The 39-year-old actress' training session was so grueling it required supervision!

Lupita Nyong'o may have made it look easy to swim in the underwater kingdom of Talokan, but to do so required Navy SEAL-like training sessions. And the proper supervision.

The 39-year-old actress and star of Black Panther: Wakanda Forever posted a 54-second clip Saturday on TikTok giving fans a glimpse of the excruciating training she underwent to perfect her role as the "war dog" spy Nakia. Nyong'o captioned the video, "Swimming down to Talokan was not as easy as it looked! Safely supervised by @XPTLife and #MarkRobertsFitness."

The behind-the-scenes clip starts with Nyong'o submerging underwater while holding what appears to be a 10- to 15-pound dumbbell. While using her left hand to hold the dumbbell to her chest, Nyong'o is left with only her right arm to swim in a straight line. You can see this type of training's not for the faint of heart. The training's so grueling, an expert swimmer's by her side the whole time to ensure everything goes smoothly.  

@lupitanyongo Swimming down to Talokan was not as easy as it looked! 🏊🏿‍♀️🌊🏝 Safely supervised by @XPT Life and #MarkRobertsFitness 🏋🏿‍♀️ #wakandaforever #blackpanther #talokan #underwater #fittok #behindthescenes ♬ Con La Brisa - Foudeqush & Ludwig Göransson

In another sequence, Nyong'o is seen using two dumbbells -- one on each hand -- to bear crawl across the pool. She then walks up the steps of the pool while perfectly executing a farmer's walk. As if that wasn't already impressive enough, N'yong'o then takes to the deepest part of the pool and performs another farmer's walk.

The clip ends with Nyong'o calmly putting down the dumbbells and swimming back to the surface. She's seen smiling before the video cuts to another angle, and that's when she reveals how the whole training makes her feel.

"I feel like a crawfish," she quipped.

Written and directed by Ryan Coogler, the sequel, starring Nyong'o, Letitia Wright, Winston Duke, Danai Gurira, Angela Bassett, Florence Kasumba, Martin Freeman, Michaela Coel, and more, explores "the incomparable world of Wakanda and all of the rich and varied characters introduced in the first film."

Black Panther: Wakanda Forever is in theaters now.