Unless you believe that old fountain of youth legend, there really isn't any way to turn back the time. But Madonna's personal trainer-to-the-stars Tracy Anderson thinks she can keep the Material Girl looking like she hasn't aged a day since the first time she sang Like a Virgin.

"I want to keep her body looking like it's 20 years old," says Tracy. "Because you don't have to have saggy arms, or poor skin tone in your 50s, or not have cute hips. It just doesn't have to happen. [A superfit body] should start being your standard when you're young - and after that, why should you ever want less?"

Though I can get behind the whole "age gracefully" movement, I like Tracy's line of thinking. We can't all have our 20-year-old bodies back, but growing older doesn't have mean giving in to gravity. Fitness is just important at age 50 as it is at age 20 ... why let those kids have all the fun?

Has your workout routine helped you defy the effects of aging?