Cynthia Erivo got just two-to-three hours sleep a night while filming 'Wicked'.

The 37-year-old actress stars as Elphaba in the two-part musical blockbuster and she told how she pushed herself to the limits, waking very early for a two-hour workout ahead of the two hours she had to spend in the make-up chair getting transformed in time for a 5am call time.

Discussing sacrificing sleep during a screening of the movie during a Q+A session with Kristen Bell at the Academy Museum's Ted Mann Theatre in Los Angeles, People magazine reports she said: "I think I consciously run towards things that will use me physically, as well as mentally, because I believe that the body and the mind are intrinsically, truly intrinsically linked.

"Sometimes the body is the thing that tells the mind what to do, and sometimes the mind is the thing that will tell the body what to do because I feel like I'm a very physical person. I want both things to be in action. I want both things to be being used."

Cynthia explained her daily workouts were necessary in order to be in the best shape possible for her flying scenes.

She said: "I had never flown before. I just knew I wanted to, I'd flown a small amount, but nothing like this before. And that requires your core to be the strongest you could possibly be, because the wires will take you from one place to another.

"JoMcLaren, my stunt coordinator, was so good with me. She was like, 'Are you sure you want to do all of this?' And I said, 'Yes'.

"And so what I would need to do is be ready enough so that when the wires are working to move me from point A to point B to point C, if we're doing a loop to loop, which is that big loop, I have to get myself over and round without my legs just falling behind me."

And the actress believes her "very boring" lifestyle made her intense routine easier.

She said: "I learned that an infrared sauna blanket is very helpful with the bruising on the inside. I learned that a therapist is also really helpful with the bruising on the inside. I live a little bit like a monk when I'm doing these things.

"I naturally don't drink or smoke or eat meat or any of those things. I'm sorry, I'm very boring, but I am in my house.

"I stay indoors and I try to take those moments when I can actually rest. I don't get very much sleep doing these things. So the two or three hours that I do get, I try to make them good quality too."

Cynthia tried to wind down from a day on set during the 90-minute process of removing her make-up, but it was "so hard" after the hectic shoot.

She said: "No days were small. There were no small days. None."