The flat bench press can develop the lower pecs when used with heavy weight.
IT Stock/Polka Dot/Getty Images
One of the most common ways to work the lower strip of the pectoral muscles, which are tough to work, involves using a declined weight bench and performing decline bench presses or chest flyes. The inverted angle allows the weight to rest directly over the lower pecs, requiring their engagement during both the lift and control phase. However, decline bench exercises aren't the only ones that can target the lower pecs.
Know Your Pecs
The pectorals are a muscle group that stretches from a point underneath your arm pits, runs across your chest and attaches at two distinct points - the clavicular head and the sternal head. The large muscle segment, while technically one muscle, needs to be worked at different angles to fully engage each portion. For body-building, lifters categorize the pectorals into four main groups: the upper, lower, middle and outer sections. Incline bench presses will develop the upper portion, while flat bench presses and chest flyes will develop the middle portion. The lower pecs can also be engaged with specific exercise.
Determine Your Schedule
Organize your workouts so that you target all portions of the pecs in the same session. You may also work out all of the other upper-body muscles along with your chest, or you may focus on just a select few muscles, like the shoulders and triceps. Avoid a schedule that has you doing flat bench presses for the middle pecs one day and then exercises for your lower pecs the next day. Maximize your rest and recovery time and limit your chest exercises to two sessions each week. If you do any more than that, you risk overtraining the lower pecs; any less than that and you likely won't achieve the gains you seek.
Take a Chest Dip
One of the best exercises that can help develop the lower pecs is the chest dip. The chest dip is a body-weight exercise that activates the pecs, the triceps and the deltoids, and it is best performed on a dip rack or a Roman chair. Since it's a body-weight exercise, you'll have difficulty using a progressive overload approach for developing muscle mass, but you can use high-repetition sets instead. Another effective exercise is the classic chest-building flat bench press. You don't need a declined angle on the bench to engage the lower portion of the pecs. Use heavy, progressive sets on the flat bench to work out all segments of your pectorals.
Use Proper Technique
To perform the dip, grip the handles of the dip rack, lock your elbows and keep your arms tucked close to your body. Slowly bend your elbows and lower yourself as far as possible. Slowly raise yourself back to the starting position. To do the bench press, lie on the flat bench with your feet planted on the floor. Grip the barbell overhand, and place your hands just wider than the width of your shoulders. Push the bar up to lift it out of its cradle and then lock your arms straight in front of your chest. Slowly lower the barbell down, stopping when it's a few inches above your sternum. Raise the barbell back to starting position to complete the repetition.
When lifting heavy weights in multiple progressive sets, get a friend or workout partner to spot you while doing the bench press or flyes. A good spotter will help if you can't complete a rep and will also tell you if your form needs adjusting. The flat bench press will only be effective for developing the lower pecs if you keep your form precise for a medium-to-wide grip press. In most cases, you won't need a spotter for standard chest dips.