How Bradley Cooper's Personal Struggles Prepared Him for Grueling 'American Sniper'

Vanity Fair

Bradley Cooper is seeing life in a different color.

The 39-year-old Academy Award-nominated actor is opening up about how his personal struggles helped him prepare for his latest role as Navy SEAL sniper Chris Kyle in American Sniper.

In January'sVanity Fair, Cooper talks about his "natural" preparation for the role after being sober for 10 years, beefing up for the part by gaining 40 pounds. Back in July, he spoke to ET about his new diet, revealing that he ate 5,000 calories a day.

It was also about building pure muscle.

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"I had a realistic conversation. Can I do this in three months naturally? Can I gain 30 pounds of fu**ing muscle? I didn't know if I would be able to do it or not. Thank God—luckily—my f**king body reacted fast," Cooper tells Vanity Fair.

WATCH: Take a First Look at Bradley Cooper in 'American Sniper' 

Beyond the physical transformation, the American Hustle star dealt with emotional pain. He lost his father on Jan. 15, 2011, and Cooper was candid about difficulties he had coping with his death.

"The bottom line is that all I got is me, so it’s about time to stop trying to be something that I think you would want me to be. Or that would give me what I think I need," he says. "As you get older, thank God, your body deteriorates, but your soul sort of flourishes."

Cooper shared what he has learned over time. "I see life much more grey as I get older," he says. "I was so sort of black-and-white in my late 20s. There’s a right and there’s wrong and that's it. That's a tough way to live."

Now, it's "really rare" for him to judge somebody: "It's sort of easy to get close to somebody if you don’t feel judged by them."

American Sniper hits theaters on Jan. 16, 2015.

Watch Cooper explain his voice work as Rocket Raccoon in box-office smash Guardians of the Galaxy.

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