Sylvester Stallone put himself through an intense diet and exercise routine ahead of filming "Rocky III" in the 1980s.

Stallone recalled what he ate and drank to keep his body fat down to 2.8% as he prepared to portray Rocky Balboa fighting James "Clubber" Lang, played by Mr. T.

"My entire breakfast would be maybe two [small] oatmeal cookies made with brown rice and 10 cups of coffee because I wanted to keep my body fat down to 2.8 percent," Stallone told The Wall Street Journal.

"I was forgetting my phone number. I was eating just tuna fish. My memory was shot, it was completely gone," the actor added. "I was getting all kinds of debilitating physical effects. But it was for the cause."

SYLVESTER STALLONE DRAFTS BREAKUP TEXTS FOR HIS DAUGHTERS, WHO ‘HIGHLY SUGGEST’ THE UNUSUAL TACTIC

These days, the 76-year-old actor focuses more on lower impact workouts.

"I’ve gone from lifting regular weights to mostly bands, cables. It’s kind of like physical therapy," he told the outlet. "So, you’re using the bar, you’re using different motions and keeping those joints moving all the time."

Over the years, Stallone has had "five back operations, two shoulders, three neck fusions, both knees," he revealed, before adding, "I’m bionic."

Stallone has also cut down on the amount of coffee he drinks.

Stallone's latest project is not as intense as he and his family star in their own Paramount+ show, "The Family Stallone." The reality show was released on May 17, just months after Stallone and his wife Jennifer Flavin almost divorced.

The couple met in 1988 and married in London in 1997. Flavin filed for divorce in August 2022. She accused Stallone of engaging in the "intentional dissipation, depletion and/or waste of marital assets which has had an adverse economic impact on the marital estate" in paperwork filed on Aug. 19.

However, by September the pair had seemingly chosen to reconcile and work on their marriage.