Do keep your upper arms pinned at your sides.
Do step slightly back away from the machine.
Do hold for a count at the bottom to contract your triceps.
Do keep your upper body motionless.
Do exhale as you push down and inhale as the bar returns to the start.
Do use a two-seconds-up/two-seconds-down cadence.
Do use a rope or a V-bar. MRI studies show that straight-bar pushdowns can slightly neglect the medial head.
Don’t allow the bar to rise higher than your lower-pec line, or your upper arms could come forward.
Don’t use momentum to get the bar moving.
Don’t lean too far forward; try to keep your torso as perpendicular as possible.
NEVER stand so close that the dirty cable leaves stripes on your face and everyone thinks you’re playing commando (see photo).