Arnold Schwarzenegger's Son, Joseph Baena, Goes on Shirtless Beach Jog with His Bros

Arnold Schwarzenegger's son must have learned from his old man -- you gotta get the cardio in if you wanna get ripped.

Joseph Baena wrapped up a workout session Friday with a run on the beach in Malibu ... along with a couple buddies who popped their shirts off to show off their muscles too.

This isn't the first time Joseph's shown he's a chip off the old block either. What can we say ... he gets it directly from his dad.