Dynamic stabilizer: Biceps Brachii (short head only)
Lie supine (on your back) on a bench inclined at 45 degrees.
Grasp the barbell using a reverse grip (palms facing you), with your hands placed wider than shoulder width.
Unrack the barbell.
Inhale as you lower the barbell to your upper abdomen.
Exhale as you press the barbell back up to the starting position.
Comments and tips
According to the information presented in the second video below by Jim Stoppani, a recent Australian study found that the standard incline bench press increased the activity of the upper pectoralis major by only 5% more than the flat bench press, while a separate Canadian study found that the reverse-grip barbell bench press increased the activity of the upper pectoralis major by 30% more than the flat bench press (unfortunately, he doesn’t provide proper references). This suggests that the reverse-grip bench press is six times more effective at building the upper pecs than the incline bench press. The above exercise—the incline reverse-grip barbell bench press—combines both the incline bench press and the reverse-grip bench press to produce what could be the single most effective exercise for building your upper pectoralis major.
The incline reverse-grip barbell bench press can be very awkward. Give yourself time to get used to it.
Start light, and use a spotter or a Smith machine for safety. The spotter will become essential when you go heavy because unracking a heavy barbell using a reverse grip is difficult.
The wide grip (not illustrated properly in the image) is essential to minimize the involvement of your triceps.
Scientists who compared chest press muscle activation at four different bench angles (0, 28, 44, and 56) found that the clavicular head of the pectoralis major is most active at 44 degrees—hence my recommendation to use an angle of 45 degrees (the closest setting).
You should also try the incline reverse-grip bench press using dumbbells, which allow you to rotate your forearms into a more comfortable position as you lower them.