Bench press is the primary exercise used to strengthen and build mass in the chest. However, limiting yourself to one exercise is not enough to create a well-shaped pectoral muscle. The inner pectoral is one area of the chest muscle that can specifically be targeted using dumbbells to create a defined inner chest.
The chest consists of the pectoralis major and the pectoralis minor. The pectoralis minor is the smaller of the two muscles and lies underneath the pectoralis major. The pectoralis major is a large muscle that consists of two heads: the sternal and clavicular heads. The sternal head is the area that needs stimulated when building up the inner pectorals. Dumbbell presses and dumbbell flys are exercises to include in your inner pectoral workouts.
The development of the inner pectorals comes from focusing your effort on the top half of the pressing movement. Begin by laying flat on the bench with your feet on the floor. Holding a dumbbell in each hand with your palms facing each other and your arms extended upward. Lower the dumbbells down to chest level rotating your palms, so they are facing your feet. Press the dumbbells back to the starting position, rotating your palms, so they are back to facing one another, squeezing hard at the top of the motion. Make sure to bring your hands as close together as possible. Complete 10 full range-of-motion repetitions, followed by 10 partial range-of-motion repetitions focusing on the top half of the repetition to isolate the inner pectorals for three or four sets.
Dumbbell flys also work well to isolate the inner pectorals. Lie flat on the bench with a dumbbell in each hand. Extend your arms above your chest with your palms facing each other and your elbows slightly bent. Lower the dumbbells out to the side, until your elbows are at shoulder height, and then bring your arms back together. Squeezing the muscles together at the top or crossing the dumbbells over slightly will help you achieve a full contraction of the inner pectorals, says Arnold Schwarzenegger, author of “Encyclopedia of Modern Bodybuilding.” Repeat for 12 to 15 repetitions for three to four sets.
Additional Inner Pectoral Exercises
The inner pectorals can effectively be trained using the above two dumbbell exercises, or isolated with barbell or cable pulley exercises, as well. Movements that involve bringing your arms close together target the inner pectorals such as cable crossovers when your arms cross over each other. Additionally, close-grip bench press in which your hands are placed shoulder-width apart or slightly less will target the inner pectorals. Replace close-grip barbell bench press with one dumbbell by grasping each end of the dumbbell and holding it directly over your chest. Lower the dumbbell to your chest while keeping your elbows pointed toward your toes then press back up and repeat.
Inner Pectoral Isolation Workout
Begin your workout with a five minute light cardio warmup such as brisk walking. Start with the dumbbell presses as stated above, followed by three sets of 10 reps of close-grip bench press. Complete three sets of dumbbell flys and cable crossovers for 12 to 15 repetitions each. Finish your inner pectoral workout with 25 close-grip pushups in as few sets as possible.