Incline presses will build the most-balanced-looking chest. Decline-pressing movements target only the lower pecs, leaving the upper chest underdeveloped.
PROSECUTION
Due to the angle of the clavicles, decline presses allow activation of both the lower and upper pecs, thus serving as the best exercise for total pec development.
EVIDENCE
To stabilize the weight overhead in an incline position, the lower-pec fibers must not contract fully. Because of the direction of the fibers making up the lower half of the pec, their contraction pulls the arms toward the feet.
In a decline position, all fibers—including the clavicular fibers—are stretched at the bottom position of the decline chest press. Thus, even the clavicular or upper fibers of the pecs contract to push the bar up from a decline position.
A study conducted at Wayne State College in Nebraska demonstrated that both upperand lower-pec fibers are engaged during decline press (-15 degrees) while only upper-pec fibers are engaged during incline press (+30 degrees).
VERDICT
Decline bench presses induce greater overall activation of the pecs compared with the incline bench.
SENTENCING
Because of the structure of the pectoralis muscle, it can and should be trained at a variety of angles. When having to choose between incline or decline presses, be mindful that because the upper pecs are engaged during both incline and decline bench positions, while the lower pecs are only engaged during decline pressing, incline bench should not serve as the sole pec movement if full pec development is the goal.
