If you want to hit a certain area of the pecs then you need to know how to target the chest with different exercises.
Keep in mind, you cannot isolate one area of the chest instead of another. When the muscle contracts, it does so in an “all or none” fashion. That said, because of the separate nerve innervations feeding the upper pecs and lower pecs as well as the orientation of the fibers in these two areas it is possible to more heavily influence one over the other.
The key to identifying whether a chest exercise you are doing is working the top or bottom of your pecs, just look at the position of your arms when you are doing it. Are your arms angled downward or below the horizontal plane or are they angled up? What I mean by this is if you were to hold your arms straight out away from your body in standing they would be parallel to the floor. If during a particular chest exercise your arms are angled below this, then you are more heavily influencing your lower pecs.
If on the other hand your arms are angled slightly up from the horizontal plane, then you are more heavily working your upper chest. Don’t be fooled by the position of your arms when you are laying down. This can be deceiving. In order to see what area of the chest the exercise you are doing is actually working, you need to stand up maintaining the same position of the arms as you had when doing the movement. Check and see where they reside when you stand and that will tell you the answer you are looking for.
Using this information, it becomes easy to see how the incline dumbbell bench press or barbell incline press is a great upper chest exercise while the decline dumbbell or barbell bench press is good at targeting the lower pecs. The situation becomes more confusing when you take this and apply it to pushups, however. An incline pushup might be thought to work the upper chest but this would be incorrect. Given that the position of the arms is down from the horizontal, the incline pushup actually works the lower chest or bottom of your pecs more readily.
Vice versa, the decline pushup is a great bodyweight chest exercise for hitting the upper chest a bit more than just regular pushups can.
This same chest workout chest can be applied to any chest exercise. Even the dumbbell chest pullover tests out as an incline chest movement. In fact, it is one of the more obscure chest exercises that I know for helping to build a thicker and bigger upper chest. The area that is seen even when you wear a shirt with a slightly low neck line.
Finally, dips are a classic lower chest exercise. With the arms held tight to your sides and pointed well below the horizontal plane you can be assured that the majority of the work and stretch is being directed at the abdominal head of the pectoralis major. Learn to also keep your shoulders from shrugging during this chest exercise as I’ve pointed out in previous videos and you are in store from some serious gains doing this chest workout classic.