How to do the Barbell Curl

Stand with your feet hip-width apart, holding a barbell with palms up.
Let the bar hang, elbows near your sides, and wrists straight.
Pull the bar up by bending your elbows, keeping your upper arms still.
Lift until your forearms are upright, then slowly lower it until your elbows are fully extended.
Repeat the movement, focusing on a smooth, controlled lift and lower.

Full technique — 6 steps

Stand tall with feet about hip width apart, holding a barbell with an underhand grip.
Let the bar hang against your thighs with wrists straight and elbows close to your sides.
Set your ribs down and keep your torso upright without leaning back.
Curl the bar upward by bending your elbows while keeping your upper arms mostly fixed.
Raise the bar until your forearms are nearly vertical and your biceps fully shorten.
Lower the bar back to the start under control until your elbows are fully extended.