Turns out TIM MCGRAW has no idea how he broke his foot. He tells CMT.com, quote, "I don't know if it happened running or in the part of the show where I jump off speakers. It could've happened any number of ways." As you know, Tim is a workout freak so when he first started experiencing pain he tried to "man up" and power through it. But that just made it worse. He explains, quote, "I kept running and kept working out and kept doing shows. "And for a couple weeks, it just kept getting worse and worse, and it finally got to where I couldn't walk, and it was really swollen." Tim's wife FAITH HILL eventually put her own foot down and insisted he go to the doctor. That's when he found out it was serious. Tim said, quote, "It started out as a stress fracture, and I kept pounding it, pounding it and pounding it, and it got worse and worse." Tim is supposed to wear a corrective boot for four more weeks, but that could stretch out longer if he doesn't STOP exercising like a mad man. He said, quote, "I think I'm not taking care of it as well as I should. "I still work out. I have a machine that's sort of like an elliptical, but it's a seated elliptical that I use a couple of times a day. Nothing replaces running, but at least it's something. And I can still lift."