In this tutorial, we learn how to build large muscles with basic hammer curls. First, stand with your back straight and lift your arms straight up and down. The muscles that will be working will be your forearms and your bicep. You can lift both arms at once, but make sure you are not swinging the weight. You want to control the muscle so that is what is doing the full lift, not the rest of your body. After you do this with both arms, start using just one arm at a time to focus on your different muscle groups. Remember to bring down the weight slowly, so you are training your muscles going down as well!