Getty Images THE USUAL PLAY when someone like me writes a program for someone like you—someone who’s just getting started, or returning after a layoff—is to promise you all kinds of wonderful things. Biceps! Abs! A hummingbird’s metabolism with a bison’s bone density! A lifetime of lifting, and a quarter-century of writing about it, has taught me never to promise any specific outcome to any specific routine. The range of potential responses is as diverse as humanity itself. Some lifters put on muscle faster than others. Some get really, really strong. With some the physical transformation toward a lean, athletic body seems sudden and dramatic, and with others it’s a slower process. Only until you commit yourself to a serious strength-training program will you see how your body responds and take your training to another dimension. The 12-week program is divided into three four-week stages, each of which builds on the one that preceded it.…