You've probably been dieting and exercising--or trying to--your entire life. You lose the weight; you gain it back. Or you lose most of the weight, but can't get those last stubborn 5 to 10 pounds to budge an inch. Or you exercise like mad, but still, the butt's a little saggy, the arm's a little flabby, and the belly's a little droopy. Why don't you have the body you always wanted? You may not know the real secrets of strength training and the magic of dumbbells....