GEORGE CLOONEY dumped his gorgeous girlfriend Stacy Keibler because her intense workout routine was driving him crazy!

That’s the REAL reason the couple’s nearly two-year romance ended, The ENQUIRER has learned.

Published reports say Stacy, 33, called it quits with the confirmed bachelor because she was ready to start a family. But she denied that, and a well-placed source gave us the inside story.

“George does NOT get dumped,” the source revealed. “What he does do with all his soon-to-be ex-girlfriends is let them bow out gracefully, which is exactly what’s happened here. They’ve been over for a lot longer than people think.”

According to the insider, George was sick and tired of ex-wrestler Stacy’s obsession with staying in shape.

“She’d get up at the crack of dawn every single day without fail and embark on an exhaustive two-hour, pro-sports-style work­out routine,” the source explained. “It got to the point where George didn’t want to spend the night with her because she would wake him up at 5:30 in the morning to get ready for her workout.

“George tried to keep up with her in the early days, but after about 45 minutes, he was ready to hit the sauna, and she was just warming up.” Eating out together was a problem too.

“George would take her to a five-star restaurant in anticipation of a blow-up meal with wine and dessert, and Stacy would just have water and a salad with the dressing on the side,” said the source. “She was way too rigid for him when it came to her health.”

Now George, 52, is said to be looking for a more low-key lady.

“He’s finding that he prefers the company of women in their 40s,” added the source. “He wouldn’t balk at dating a divorcee of that age who’s ready to have some fun.”