Filming 'In The Heart of the Sea' wasn't for the faint of heart

Filming "In the Heart of the Sea" clearly wasn't for the faint of heart.

"In the Heart of the Sea" is a true story about a 19th-century whaling vessel called the Essex. After the Essex is demolished by a whale, the crew must deal with weather, water and a lack of food.

Chris Hemsworth had just finished filming "Blackhat" and had to lose a lot of weight for this movie — even more than he does when playing the role of Thor. That's because the actors could only eat 500 calories a day in order to make it look like they were starving.

That's not all that "Heart" co-star Tom Holland had to deal with. His character has to enter a dead whale to extract oil from it. Holland says it took the crew 15 minutes to get him out of the fake whale because it was incredibly slick. And this happened at 1 a.m. in November, so he was very cold and covered with a jelly-like substance. To make matters worse, director Ron Howard said he had to do it all over again two weeks later.

It sounds like we'll have way more fun watching it than they did making it when "In the Heart of the Sea" starts its voyage on December 11.