Begin the setup of the exercise by placing two dumbbells on the ground in front of a flat bench. Sit on the edge of the flat bench (facing the dumbbells) with your legs approximately one shoulder width apart. Keep your feet planted firmly into the floor. Grab both of the dumbbells with your palms facing downwards (this is called a pronated grip) and bring them up so that your forearms are resting on your thighs with your wrists hanging slightly beyond the end of the your knees. Begin the exercise by curling your wrists upwards. Once you have curled the weights as high as you possibly can, hold the peak contraction briefly before slowly lowering your wrists back down to the starting position. Ensure that, throughout this exercise, you are not moving your forearms or any other part of your body. Repeat for the prescribed number of repetitions.
One variation of this exercise involved using a barbell instead of dumbbells.