If this product sounds familiar, that's because it is. The Ab Doer Twist ($150) is an upgrade to the Ab Doer created 12 years ago. The secret to this machine is . . . biometric synergy with the promises to build muscle, tighten your core, and burn calories, in just minutes a day, of course. Don't fall for this pricey product. As I've said before, save your dough and do free ab strengthening moves combined with cardio to slim your middle.