A saggy lower chest makes even the biggest of pecs look underwhelming. Sometimes, a lack of development in the lower region of your pecs indicates that you need to add more muscle to all of your chest, not just this specific region. But, if you know you've been skimping on your low chest development, you're in luck.
Certain moves will help you hone in on the lower pecs to add thickness to this low-volume region. Presses and flyes done at a decline are particularly valuable.
Lower Chest Training
The lower chest isn't a separate muscle. It's the bottom portion of the wide pectoralis major that spans the entirety of your chest wall. When your goal is to build up this area, start your chest workout with a move that specifically targets it. Then, move on to other chest exercises that address the whole of the chest wall -- including flat bench presses and the pec deck machine -- but ensure you include at least one other lower-chest specific exercise in your chest workout that day.
A typical chest-centered workout includes three to five total exercises. Work up to three or four sets of eight to 12 reps using a weight heavy enough to make the last few efforts hard to do with good form. Remember to leave at least 48 hours between chest workouts to give the muscles time to repair and build.
If you've been training this way for a while, it might be time to switch things up. Load up heavier weight and make the sets contain just three to six reps. Super-setting is another option. This is where you do two exercises back to back with no rest between them. Then, rest before completing that pair and moving on to another. Consider decline chest presses and incline push-ups as a possible couple, for example.
The key to lower chest training is to target the pectoralis major muscle from a different angle. Putting your body in a decline position, with your feet higher than your chest, forces the lower portion of the pectoral muscle to work against more resistance. In the case of push-ups, however, your body needs to be at an incline to target the lower chest.