3) Preacher curls

The aim of this exercise is the lower end of the biceps. The execution needs to be even stricter than in the case of the standing curls.
The subject sits down at the preacher bench, with the arms over it, chest pressed close to the arms-support, takes hold of an E-Z bar or a regular straight bar (about shoulder wide underhand grip). He/she then curls it up and to the front slowly until he/she reaches the top of the movement. The biceps are best of being flexed a little bit there, then he/she slowly lowers it to the starting position.
Extra considerations: - cheating in this exercise comes in the shape of the subject getting off the seat and then slumping back as the weight is lifted. Try to avoid that. That again reduces the range of motion.