Stand up straight with your feet shoulder-width apart and hold a barbell with an underhand grip, hands close together.
Keep your elbows close to your torso and your upper arms stationary throughout the movement.
Exhale as you curl the weights while contracting your biceps. Continue to raise the bar until your biceps are fully contracted and the bar is at shoulder level.
Hold the contracted position for a brief pause as you squeeze your biceps.
Inhale as you slowly begin to bring the barbell back to the starting position.