The world is Christie Brinkley’s gym, the supermodel explained to Shape magazine. “I think of drying my hair as really boring. I thought, 'OK, I'm going to multi task.’ I'll dry my hair as though I'm sitting on a chair, even though there's no chair there. Then I'll do some squats. When I am brushing my teeth, I'm bending my leg behind me, or I'm lifting my leg up and holding it in that position so I'm squeezing my butt in. I can do that while I'm washing or slicing vegetables, too. Or I go up and down on my toes, working my calves a little bit." This probably means she eats a lot of vegetables, too. [Shape]