Eminem was struggling with drug addiction when he reached his highest weight of 230 pounds and came close to dying from a pill overdose. Several years later, he's finally opened up about his weight loss journey and how he dropped 81 pounds to get back to the "Real Slim Shady." The 42-year-old rapper was in the hospital at his heaviest point in 2007 when he overdosed. He'd been taking pills, including Vicodin and Valium, for years and was constantly eating to avoid getting a stomachache from the drugs.

He recently sat down with Men's Journal and explained how he started running to help his sleep pattern and it ended up giving him a "natural endorphin high," so it was perfect.

"When I got out of rehab, I needed to lose weight, but I also needed to figure out a way to function sober," he told the magazine. "It's easy to understand how people replace addiction with exercise. One addiction for another but one that's good for them. I got an addict's brain, and when it came to running, I think I got a little carried away I became a f**king hamster. Seventeen miles a day on a treadmill."

After he became almost too addicted to running, and even got "OCD about the calories," he needed to find a new way to work out because he started to hurt himself, in particular his hip flexors.

He eventually got into DVD workouts like Shaun T's Insanity, P90X and Body Beast and thanks them for helping him get in the best shape of his life at 42. "I know a lot of these DVD guys are wacky, but I'm alone in my gym," he said. "I need someone on the TV yelling to motivate me Besides, some of this s**t is entertaining."

He's become so used to his workout routine that he's afraid if he stops for even just a few days, it'll feel like "starting over."

"I'm afraid that if it goes beyond that, I might lose the motivation," he reveals. "Once you're at a place where you've made progress and you've got some time invested in it, you don't wanna quit and give up what you started."

All this comes just a week after the boxing film "Southpaw" was released, which features a soundtrack that Eminem is an executive produced on, according to Rolling Stone. Considering he's in amazing shape again, the rapper was actually asked to star in the film at one point, but he let Jake Gyllenhaal have the role so he could solely focus on the music.