You should ... because the NHL star's in the kitchen with The Rock -- and by "kitchen," we mean the gym -- and the video is awesome.

The two -- along with P.K.'s fiancee Lindsey Vonn -- got in a private pump sesh with the WWE legend at an empty gym in L.A.

This particular clip was shot at the lat pull down machine -- where Rock gave PK a spot and some personal training tips while Vonn shouted along some words of encouragement.

Side note ... anyone got some scotch tape handy? BECAUSE P.K.'S BACK IS RIPPED, SON!!!

Of course, P.K. posted the footage after the workout -- saying, "Today, I became a man."

It's like a gym Bar Mitzvah.

the workout went down at one of The Rock's own personal gyms ... which he likes to call the Iron Paradise -- AKA, the Willy Wonka candy factory for muscleheads.