Amber Heard's 'Aquaman' training was "rigorous".
The 31-year-old actress stars as Mera in the upcoming DC Extended Universe movie, and was so determined to "deliver for the character" that she would train "non-stop" for hours to get her body in shape for the role.
Speaking to People magazine, her personal trainer Gunnar Peterson said: "She wanted to deliver for the character. [She trained] for a non-stop, no breaks hour with me, and then she went to her fight training, which was rigorous! Everything was athletically based. We trained movements, not muscles. Squat presses, sled work, and lots of work in a rotational plane against resistance. She is a true athlete. She was so consistent. Without her being so committed, the results would not have happened. She could not have been better! If I could bottle her drive and conviction I'd sell that as a pre-workout drink!"
Amber will make her first appearance as the Queen of Atlantis - and the love interest of the titular Aquaman, played by Jason Momoa - in the DCEU ensemble movie 'Justice League' later this year, before starring in the standalone movie in 2018.
Previously, 'Aquaman's screenwriter Will Beall insisted the movie will "blow people's minds" as it's going to have a lot of humour whilst also being massive in terms of its "scope".
He shared: "It's going to be fun, it's going to be really fun. What we've come up with and James especially - he has a really clear idea of the tone he's going to have, and I think 'Aquaman' is one that's going to blow people's minds, not just visually, but I think the story and the scope of it is really great."
The feature - which began shooting last month - is also set to star Willem Dafoe as Altantis' chief scientific adviser Nuidis Vulko, as well as Patrick Wilson as the titular character's evil half-brother Orm Marius, who is also known as the Ocean Master.
'Aquaman' is expected to hit screens in December 2018.