Quadriceps
Calves, Glutes, Hamstrings
Place barbell across upper back (traps).
Stand facing sturdy box/bench.
Place one foot (e.g., right) fully onto box.
Push through heel of front foot to step up, bringing other foot onto box.
Keep torso upright, core engaged.
Step down with trailing foot (left), then lead foot (right).
Repeat, leading with same foot for desired reps, then switch.
Maintain control.