Grab the handle of a cable that has a low attachment, about ankle level with your right hand. Stand tall with your cable at your right side with your feet about shoulder-width apart. Stand far enough away from the cable so that it's at roughly a 45-degree angle to the floor.
Without rotating your body, bend your torso sideways to the right until you feel a mild stretch in the left side of your torso. Reverse the action and finish the rep by slightly flexing your torso to the left against the resistance.
There's not much resistance when you're standing upright holding a dumbbell because the dumbbell is very close to your body, giving you a huge mechanical advantage over the weight. But when doing them with a cable the angle of the cable forces you to work hard to stay upright and maintain that position between reps, giving you more time under tension through the range of motion.
If you want to build huge muscles, you must continually challenge them by placing a greater demand upon them. If you stick with the same stress level month after month, you'll quickly reach a point where your body is used to the stress and won't need to adapt (i.e. grow) anymore.
When it comes to exercise performance, especially the more exotic movements I often prescribe, most people grasp the big picture but miss the finer points. To remedy this, I created this "toolbox" series to help experienced lifters fill in the blanks and newer lifters learn about some very effective exercises. Here's the newest installment!
You've seen his name on a lot of recent T-Nation articles, and you've seen him pass out some outstanding training advice on the forum. And you've probably thought, "Man, that guy is smart, but who is he anyway?"