How to perform the exercise
Stand straight holding a barbell with an underhand grip, your hands shoulder width apart and your arms fully extended towards the floor.
Keep your elbows close to your sides.Your palms should be facing away from you. This is the start position.
Keeping your upper arms stationary, curl the barbell forward and up in a smooth arcing motion while exhaling. Only your forearms should move.
Continue upwards until the bar is at shoulder level with your biceps fully contracted. Hold for a count of one while squeezing your biceps.
Inhale as you return to the starting position.