Go for gold
As contentious as the Academy Awards can often be, full of grandiose speeches and unfortunate musical numbers, there's little doubt that the brilliant actors and actresses that the show gets around to awarding are plenty deserving of the prize. You don't get to this point without being seriously committed to the craft - Leonardo DiCaprio finally bagged himself an Oscar last year after eating raw bison liver for his role in The Revenant, basically daring the Academy to not give him the gold, and he's not the first to go to such extremes.
In fact, he's not even the most terrifying case. The roster of Academy Award winners is packed with folks who gave their all to a role, and a few who went to legitimately terrifying lengths for that Oscar-winning performance. Injuries, isolation, and regimens so intense they end in emotional instability are just another day on the set - they deserved that Oscar, and nothing was going to stand in their way.
Daniel Day-Lewis never broke character on the set of My Left Foot (but did break some ribs)
Simply calling Daniel Day-Lewis a method actor would be like describing the Grand Canyon as a hole in the ground - technically true, but a vast understatement. Day-Lewis is famous for how deep into character he gets, to the point that his fellow actors don't actually get to meet 'him' until the wrap party.
He took things to frightening lengths with his performance in My Left Foot, where he played paralyzed Irish Artist Christy Brown. Refusing to break character, Day-Lewis spent every moment on set in a wheelchair, requiring regular spoon-feeding from cast members, to the point that he broke several ribs by maintaining a consistent, painful hunch for so long.
Natalie Portman worked out five hours a day for six months for Black Swan
It takes years of training, steadfast dedication, and a fair share of broken toes to make it as a ballerina, and apparently Natalie Portman was looking to make up for lost time. Six months before filming began on Black Swan, Portman started an intense training regimen, working out five hours a day, every day leading up to the shoot.
That's nine-hundred hours, or over one solid, uninterrupted month of nothing but exercise - and that isn't even when the injuries started. And I whine about going jogging in the afternoon.
Matthew McConaughey almost lost his eyesight for The Dallas Buyers Club
Losing an incredible amount of weight isn't as extraordinary in Hollywood as it should be, and Matthew McConaughey isn't even the most extreme case in recent years (that honor may very well go to Christian Bale, who got down to the weight of a large Pomeranian for a role in The Machinist). However, that isn't what made McConaughey's case so terrifying - going from well-toned heartthrob to an emaciated AIDS patient for The Dallas Buyers Club almost cost him his eyesight, and he still hasn't fully recovered it.
This was likely due to a Vitamin A deficiency, which can cause blindness over time if allowed to persist. Given that McConaughey was essentially going on a crash diet to look as malnourished as possible, it's not an entirely shocking development. Still a completely terrifying one that should make you think twice about dropping pounds fast!
Hilary Swank trained so hard for Million Dollar Baby that she gave herself a potentially lethal infection
When she was cast as the steadfast, stubborn, and incredibly talented heroine of Million Dollar Baby, Hilary Swank was determined to prove she was right for the role - even if it killed her. Following instructions from director Clint Eastwood about bulking up to make herself look like a proper boxer, Swank took on a workout regime not unlike Natalie Portman's - five hours of training a day to prepare for the film, which eventually gained her 19 extra pounds of pure muscle.
Of course, work like that can have consequences, especially when you don't give yourself a break. Swank eventually contracted staph infection through an open blister on her foot, which doctors warned her could ultimately be fatal. But Swank kept training anyway, didn't tell Eastwood about it, and stuck with the role. Thankfully the infection cleared up, leaving her healthy enough to claim her statue later on.
Adrian Brody abandoned his home and life for months to nail his role in The Pianist
Adrian Brody went the distance for his part in The Pianist - as in, the distance between New York and Europe, and with very little baggage. In order to really put himself in the worn-down shoes of Wadysaw Szpilman, a Polish Jew who loses his home, family and livelihood during the Holocaust, Brody abandoned all of the trappings of a comfortable life. And I don't just mean nice furniture and Netflix - he sold his apartment and car, cut off his phone service, packed a couple of bags, and flew to Europe to live off nothing.
Brody ultimately said the effort was worth it, as it made it possible to play arguably one of the most important roles of his career from a place of genuine understanding (the Oscar probably helped too). Nonetheless, it all took a noticeable toll, with Brody noting that "It took over half a year after the film was done to settle back into" normal life.
Kate Winslet couldn't mentally handle the real world for months after finishing The Reader
Brody isn't the only one to have struggled with a return to normalcy, or to do it after the intensity of acting in a WW2 movie. Kate Winslet bore a similar emotional weight after her performance as a former Nazi concentration camp guard in The Reader, which she committed to so entirely that she wasn't ready to fully return to her real life for months afterward.
"It's like I've escaped from a serious car accident and need to understand what has just happened," Winslet told Contactmusic.com, explaining that she regularly fell into deep emotional ruts in the weeks immediately after filming ended. "When I leave a character, I have to analyze the trance through which I have just passed. It can take me several months to say goodbye to them."
Brie Larson went into full isolation to understand her character in Room
Brie Larson literally locked herself away to get her role in Room Oscar-ready. Playing a woman locked in a tool shed with her young son for seven years, Larson knew that she wouldn't really be able to grasp such a unique psychological situation without some sort of example. So she decided to make her own, locking herself in her house and having no contact with the outside world for a full month.
While chilling out at home with no responsibilities for a month doesn't sound so bad (and Larson was expecting exactly that, saying she was looking forward to a "vacation"), the actual realities of isolation are pretty horrific - the complete lack of human interaction or outside stimulation left her emotionally distraught to the point of depression, and she spent a good chunk of that free-time crying uncontrollably.