Shoulders

A heavy overhead press and a heavy lateral raise train the shoulder in almost opposite ways, and the contrast between the two says more about the deltoid than either lift on its own: the press moves far more weight, but splits that effort across the front deltoid, the triceps, and even the chest once the angle drifts toward horizontal, while the lateral raise doesn't share the load with anyone — it hits the side deltoid almost exclusively, the part that gives the shoulder its rounded shape and the part that gets the least real work from any press. Horizontal pressing, like a flat or incline dumbbell bench press, barely touches that side deltoid at all; the overhead press does add something, since the arm travels overhead, but noticeably less than a dedicated lateral raise, which is why a strong presser can still end up with a shoulder that looks small if lateral raises never make it into the program. A shrug that finishes off a lateral raise — letting the shoulders creep up — shuts the deltoid down right when the weight is asking the most of it. Overall, the shoulder runs on three patterns that rarely get confused with each other but do get trained in uneven proportion: pressing overhead, pressing horizontally — where the shoulder only assists — and raising the arm out to the side without pressing anything at all. Across the presses, the angle of the arm relative to the torso decides how much shoulder gets involved: the more vertical the press, the more front deltoid it demands; the more horizontal, the more the chest takes over.