Training the lower lats, where the muscle lays along the back side of the ribs and begins to arc toward the upper arm, adds thickness to the muscle. This thickness emphasizes the appearance of a wider back and narrow hips, what bodybuilders refer to as sweep. To train the lower lats, use a pull-down machine and pull the bar toward you in an underhand motion to activate the lower lats. This rotates your elbows inward. When your elbows are rotated outward, as when doing wide-grip pull-downs, the upper lats are activated.
Grasp the pull-down bar in a reverse grip, with palms facing toward you. The distance between your hands should be slightly narrower than shoulder width.
Pull the bar down to the top of your chest, keeping your elbows close to your ribs throughout the movement. Move the bar as quickly as possible.
Pause at the bottom of the movement, with the bar resting on the lower portion of your chest.
Return the bar to the starting position in two seconds. Let your arms fully extend to the starting position, but don't let the weight rest on the weight stack. You want your lats to be under continual tension throughout the exercise.
Complete five repetitions using a weight heavy enough that you can barely complete the fifth repetition.
Rest for two minutes after you complete the fifth repetition. That is your first set. Complete four more sets of five repetitions, resting two minutes between each set.
Use the same rep/set scheme to train the lower lats using barbell rows and mixed-grip dead lifts.
Think of pulling down and back with your elbows to emphasize the lower lats.
While the first portion of the exercise is dynamic, do not slam the bar into your chest. Pull fast during the initial pull, gradually decreasing speed as your hands approach your chest.