Barbell Shrug: With an overhand grip, hold a barbell in front of your thighs. Your hands and your feet should be spaced about shoulder-width apart, and your knees should be slightly bent. While keeping your arms straight, lift your shoulders up toward your ears as high as possible. Hold the contraction for a second before lowering the bar back to the start.
Behind-the-Back Barbell Shrug: With an overhand grip, hold a barbell behind your thighs. Your hands and your feet should be spaced about shoulder-width apart with your knees slightly bent. While keeping your arms straight, lift your shoulders up toward your ears as high as possible. Focus on pulling the bar up and slightly behind you. Hold the contraction for a second before lowering the bar back to the start.
THE EVIDENCE
Due to the position of the bar, these two types of shrugs hit the traps a little differently. It’s critical to remember that the traps are a diamond-shaped muscle group that has an upper, a middle and a lower portion. The upper traps are seen from the front and are responsible for raising the shoulders up. The middle traps are seen from the back, and they pull the shoulder blades together.
Shrugging with the bar in front of your body causes your shoulders to round forward a bit. You use more of the upper trap muscles, as well as the serratus anterior (as it is responsible for pulling the shoulders forward).
Behind-the-back barbell shrugs cause you to lift your shoulders up and back, hitting the upper traps and the middle traps a bit. This form is awkward, so it limits the amount of weight you can lift.
Therefore, to work your upper traps to the max, the standard barbell shrug to the front is the better option, as it allows you to lift much heavier weights.
THE VERDICT
Both versions of the barbell shrug are effective for building the traps, as they both hit them from a slightly different angle, which builds different muscle fibers.
For balanced traps developed from all angles, include both versions in your trap-training program. To build bigger/higher upper traps, the barbell shrug to the front is the winner. To build thicker traps and to hit the middle portion of them, the behind-the-back barbell shrug is a better choice.
Consider doing shrugs in a Smith machine, as well. Performing Smith machine shrugs to the front can allow you to go even heavier; doing Smith machine behind-the-back shrugs can allow you to get your body farther forward away from the bar, helping to move your butt out of the way and allowing you to pull the bar higher and your shoulders back more for better middle trap development.
