The preacher curl mainly focuses on your biceps, including the lower part of your biceps known as the brachialis muscle. .
This is a plate loaded machine, so first of all add an appropriate weight for you. Adjust the seat so that your feet are firmly on the groun, whilst making sure your elbows are in the center of the rest (not too low or too high). Once ready, grab the bar with both hands, keeping your elbows on the pad pulling upwards towards you - squeeze and then lower back down in a controlled movement.