There are several variables to consider during an exercise. Sets, reps & weight (volume) are the most common and usually the only factors that get consideration. Others variables that are often overlooked, but deserve consideration are tempo, the range of motion (ROM), and intensity.
Controlling the tempo, ROM, and intensity of an exercise can be the difference between progression and plateau.
During this barbell shrug, I like to pause at the top for 2 seconds then slowly lower the weight about 3/4 of the way down while maintaining tension on the trapezius (traps). I’ll use a weight that I can do about 12 solid reps with then I rest for about 45-60seconds before I do the next set.
By controlling the speed of the exercise (tempo), the ROM, and the rest time (intensity) you can achieve more hypertrophy (muscle growth) compared to only controlling volume.