Get ready to throw away your Girl Scout cookies, normies ... 'cause Sylvester Stallone's out here muscling 100-POUND WEIGHTS in his private gym -- and crushin' it like Rocky in his prime!!
Hard to believe, but Sly's already 71 years old ... but that hasn't slowed down his workout routine, clearly.
Regular pull-ups (or chin-ups if you're a workout nut) ain't enough for the senior Italian Stallion ... so, he strapped the weight of a small human around his waist and LETARIP!!!
What's even more shocking ... Sly captioned the vid -- "Another easy workout! You’re only as old as you and your joints feel!"
Not as savage as the 1-armed pull-ups ... but pretty damn impressive.