Louis Koo shared that one of the most challenging things about filming his new movie, “Warriors of Future” (previously reported as “Virtus”) is the heavy costume they had to wear all the time.

As reported on Oriental Daily, the actor, who recently concluded filming the movie in mainland China, shared that he and co-star Sean Lau had to wear a heavy mobile armour daily for their role, whether they’re indoors or filming outside in the scorching heat.

“On the surface, it weighs over 30 pounds. But after putting it on, and if you added the sweat, it’s almost 40 pounds!,” he said.

He added that the heavy armour was also pressing his chest, making it harder for him to breathe.

“When you’re indoors with very little air, it’s hard to breathe. I often had to drink cold water to cool down,” said Louis.

To prove his point, Louis said that even Sean Lau, who would usually keep his costume on until he finishes his scene for the day, couldn’t bear to wear it for a long time.

“Sean and I would often feel the pain in our shoulders and neck. It really is too much,” he added.

The upcoming sci-fi movie, directed by visual effects artist Ng Yuen Fai, is set for release in 2019.