What if you used to be really fit and now you're not? What if, as the years have gone by, you've added a couple of pounds here and there, and you suddenly notice you're 30 pounds heavier than you were at your 10th high school reunion? Or, what if you've never enjoyed the idea of exercising, exercise

Bob Barker, beloved host of The Price Is Right, recently made headlines by announcing his retirement after 35 years. "Barker irreplaceable!" blared the entertainment tabloids. And yet, Mr. Barker celebrated his 82nd birthday a few months ago.Eighty-two! Who really are the "seniors" among us? And what