Sylvester Stallone had a truly insane diet when filming "Rocky III." Christopher Polk/Getty Images

You won’t believe what legendary movie star, writer, director and producer Sylvester Stallone put himself through to look the way he did in “Rocky III.”

Stallone waxed nostalgic in a recent Instagram post, showing off a photo he previously didn’t even know existed, detailing what he put into his body during the filming of that movie.

“Just for fun… A flashback from Rocky three,” Stallone wrote. “Between rounds I would get lightheaded and quite exhausted. I was on a very high protein diet which did not provide Much physical or mental energy. During the period I only ate very small portions of oatmeal cookies made with brown rice and up to 25 cups of coffee a day with honey and a couple of scoops of tuna fish. Sounds incredible right? At the time my body fat got down to 2.9 which is a really dangerous level. I may have looked pretty good on the outside but inside it was very dangerous thing to do. But I wanted the movie to be about change. How people have to adapt to different challenges because if they don’t they will be conquered. I will always believe the adaptation is the key to survival and that’s what this story was all about … and while, getting smashed by Superstrong,CLUBBER LANG continuously four months of rehearsal plus the fight, tended to wear a person out so I would literally go to the corner between rounds, when I wasn’t directing and try to get some blood back into my head so I could carry-on with the complicated fight choreography … It’s funny, I never knew this picture existed!”

The “very small portions of oatmeal cookies made with brown rice” was bad enough.

But TWENTY FIVE CUPS OF COFFEE A DAY!?!?!?!

That’s some next-level stuff right there.

On that note, it’s time for our coffee break. We need some extra time to step back and let this absurd tale of dedication absorb into our psyches, anyway.

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