This is a basic exercise that allows to build a significant amount of trapezius muscle.
Stand straight in front of a barbell that is placed on the floor or on a stand.
Grasp the bar in a palms-down grip slightly wider that your shoulder width.
Hold the bar with your arms straightened and extended down.
Stretch and lower your shoulders.
Make sure your knees are slightly bent, your chin pointed up.
Inhale, tighten your abs and, as you exhale, pull your shoulders up.
Pause for 2 seconds at the top.
As you inhale, return to the starting position.
Do not rotate your shoulders. Your goal is to lift them up, don't swing them to the sides.
If you do deadlifts, this exercise can be excessive, as it will make the shoulders visually narrow.