Stand facing a box or bench with a barbell on your shoulders. Ideally, the height of the box/bench would be such that when you put your foot on the box/bench, your knee will make a right angle.
Leading with your right leg and keeping your torso upright, exhale as you slowly step up onto the box/bench.
Bring your feet together on the box/bench.
Leading with your right leg, inhale as you slowly step down off the box/bench.
Bring your feet together on the floor.
Repeat the process of stepping up and down off the box/bench, making sure to alternate the leg with which you step up and down.
Comments and tips
The barbell step-up can be dangerous for the obvious reason that you can easily lose balance and drop the barbell. Therefore, start with the dumbbell step-up, then graduate to the barbell step-up without using weight plates. Add the weight plates only after you have mastered balance, and always keep this exercise light.
Use the barbell step-up to develop balance, coordination, a strong core, and the unilateral functional strength of your lower body.
Keep your feet and knees pointing in the same direction, and keep your body upright.
Control the movement of slowly lifting and lowering yourself as much as possible. Do not spring up onto the bench or allow yourself to drop back down. If you can’t control the movement slowly without springing up or dropping down, use a lighter weight.
To emphasize your quadriceps, stand close to the box/bench; to emphasize your gluteus maximus, stand farther away from the box/bench. Activation of the gluteus maximus is also emphasized if the box/bench is tall.