The line comes from the 1977 bodybuilding documentary Pumping Iron, in which Arnold Schwarzenegger compares the satisfaction of training and competing to sexual pleasure. Shortened versions later circulated online as reaction audio, with captions often paraphrasing the original wording as “I’m nutting day and night.” The clip remains recognizable because Arnold delivers the comparison with complete confidence rather than as a conventional joke. That straight-faced intensity makes it easy to reuse in gym edits, ironic motivation posts, and exaggerated reactions to pleasurable routines.