Shaquille O'Neal Curls Reggie Miller, 'I'm In The Gym!'

Who needs weights when you've got an NBA Hall of Famer sitting around!?!

Shaquille O'Neal proved he's still the "Big Aristotle" at 50 years old ... 'cause the legend just curled Reggie Miller -- with ease!!

A video of The Diesel's recent swole sesh was posted to the 'NBA on TNT's Twitter this week ... and for someone who's been retired from the NBA since 2010, Shaq looks to be in great shape.

In the clip, you see the legendary Pacers guard jump into Shaq's arms -- O'Neal didn't budge a bit -- and the former Lakers big man completes 4 full curls!!

"Don't drop me man," Reggie said, before leaping into Shaq's arms.

During his career, Shaq was one of the most dominant forces in NBA history, breaking backboards, blocking shots, and routinely punishing defenders who challenged him.

However, and he'll admit, fitness wasn't always Shaq's priority, especially as his career waned and he started bouncing around from team to team after his prime.

But, that's a thing of the past, because O'Neal looks shredded for a 50-year-old, and the way he was able to curl Miller -- who weighs close to 200 pounds -- was pretty sick.