Hulk Hogan's 65 years old and has wrestled for 4 decades ... but his son, Nick, tells TMZ Sports the WWE Hall of Famer will NEVER RETIRE from the sport he loves.
"He always says he loves it. He loves training. He loves the wrestling business. It runs too deep in his blood. I don't think he'll ever quit," Nick told us at LAX.
Of course, Hulk just made his return to WWE after being fired in 2015 ... appearing at the 'Crown Jewel' event in Saudi Arabia, and you could tell he was back in his element.
Well let me tell you something, BROTHER....@HulkHogan is in the house, and he's hosting #WWECrownJewel! pic.twitter.com/XRSEbW7eRc
Nick agrees ... and says he's still impressed with his dad's athletic ability and physical appearance.
"Everybody thinks it's a joke, but he's still over 6'5 and over 300 pounds, he's just a monster, and he's strong. It's just insane."