One of the main exercises that will help pump up the inner part of the chest is the pushup. Most likely, you have already included the load in your own training, but may not have paid attention to the fact that the different position of the hand loads are not the same chest muscles. To touch the muscles of the inner surface of the chest, you need to put your hands at shoulder width, and slightly narrower. There is a variant of this exercise in which one hand is placed on top of the other. The position of the feet, convenient for you to complete push-UPS can be any of: on knees, on toes feet on the bench. Do 3 sets of 10-15 times.
Sit on the right thigh, legs slightly bend knees, put left hand on waist, right hand rest against the floor. With an inhalation, lift your hips up, stretching his whole body in one line. Hold this position for 1-3 minutes. If physical training allows you to do push-UPS on his right hand, then bend and unbend the elbow several times. Repeat the exercise, leaning on his left hand.
Sit on the buttocks, legs straighten, lean back on his hands. On the inhale lift the buttocks up, stretched out in the pose "bar". Focus you have only on palms and toes. Hold the pose for 1-3 minutes. Then bend your elbows and start doing push-UPS, directing the back to the floor. Watch the buttocks, not sinking into the hip area. Do 15-20 push-UPS.
For the following exercises you will need dumbbells. Lie on your back, stretch your arms with dumbbells up to chest level. Inhaling, arms out to sides as you exhale, bring the dumbbells together. Do 3 sets of 10 repetitions.
Lie on your back, put your knees and heels together, hands behind your head. Put your foot on the right thigh, the upper body remains on the floor. With the exhale lift your upper body up, inhale return to starting position. Repeat the exercise 20 times and put your foot on the left thigh.