you're putting more stress on the so use preacher curls as its details peak exercise you can be sure not to you so much weight you risk putting too much stress on the elbow joint yes when you do preacher curls you can use the barbells and EZ curl bar or you can further isolate each biceps muscle by doing preacher dumbbells hurled one arm at a time yes just well you'll find a variety of different curled machines and most well-equipped gym these machines allow you to do pearls against smooth continuous resistance and Nitric Max Muscle frequently features some kind of scam created variable resistor as with other machines like these they are best used for higher RAM lower resistance finishing off said with machine girls you should expect to build a great deal mass and strength so instead go fo