Tom Cruise had to eat "three dinners" every night while filming tough stunts for 'Mission: Impossible - Fallout'.
The 55-year-old actor is already an accomplished pilot but spent 18 months learning how to fly helicopters for a sequence in the next installment of the action franchise, and the adrenaline of shooting the scenes left him with some "fascinating" side-effects.
He explained to Total Film magazine: "The adrenaline was going so hard that I would finish at the end of the day, and I'd have to go home and eat three meals.
"I'd have to have three dinners. My body couldn't get enough food and my legs ached from adrenal fatigue. It was fascinating."
It wasn't only learning to fly the helicopter that Tom had to get to grips with.
He said: "I hired guys to teach me how to do acrobatics in helicopters.
"Then we went to New Zealand, because that's the only place that would allow us to film there.
"I'm also not just flying helicopter, I'm performing in the scene."
Tom is renowned for doing his own stunts, but left the crew terrified when he was undeterred by the failure of camera rigs which had been designed to safely film him on a motorcycle, and simply took off on the vehicle anyway.
Director Christopher McQuarrie recalled: "I turned to Tom and said, 'What do we do?' He just looked at his watch and was like, 'We've got to shoot man.' He got on the motorcycle and took off.
"We ended up with a much more visceral sequence. I was really surprised at how well it played.
"When I was shooting it, I was like, 'It's just a guy on a motorcycle,' but then you see the sequence when it's put together and you're like, 'Jesus, he should be dead. This is ill-advised. We should never have done this.' "
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