Everybody’s body composition is different, and with experience you will find which of your muscle groups react better to training. The upper chest is a common weak point in most people’s body composition, meaning that even a normal training routine will leave the upper chest muscles in this region underdeveloped.
To give special attention to your upper chest muscles you should incorporate three specialization exercises at the end of your normal chest workout. These additional exercises ensure that your upper chest has had a proper workout. You should still do your normal bench press and barbell exercises before moving onto these specialization training exercises.
All three exercises require use of the pulleys at your gym. The first is the Low Cable Pulley Reverse Pullover. Place your seat at an angle so that you hit the upper chest muscles and ensure you always maintain the 5 points of contact for stability – head, back, butt, and feet. When doing the exercise remember to use your arms as a lever. Rather than bending your arms, the lever ends at your chest so put your mind in your chest. Feel the muscles in your chest contract, as it is this contraction that ultimately builds your muscles.
The second exercise is the Straight Bar Reverse Pullover. The same goes for this exercise, use your chest to pull the bar not your arms. If you are having troubles you should probably lower your weight. This will ensure correct posture and that the correct muscles are used. Note that with poor posture you are more likely to build your shoulder or arm muscles as you will overcompensate for your weak chest muscles.
The third exercise is Incline Cable Stabilizer Push-ups. This is perhaps the best exercise at it ensures the muscles in your upper chest are constantly contracted. Place a bench behind you and put your feet on them so that your body is horizontal before lowering for the push-up.
By the end of your workout you should be unable to lift your arms. Make sure to rest and give upper chest muscles time to recover and grow between workouts. One hard session per week is enough for the chest, and with proper exercise diet and rest you will see the gains of these additional exercises within 4 weeks. This being said, the immense gains of these specialization exercises with diminish after 4-6 weeks meaning that after this time they will no longer be so productive. After incorporating them in your workout for this time, break from them until you feel your upper chest needs another boost.