When someone asks you to “make a muscle,” you don’t roll up your pant leg and flex your calf or hunch over and show off your traps—you flex your biceps, dammit. And that’s why I’m never shocked when I witness average gym rats screaming and cursing during sets of curls, training their biceps with more intensity than they do any other body part. It’s the quintessential muscle, the mark of a guy who lifts. Everyone wants a nice pair of sleeve-huggers, and that’s fine by me. With that said, here are a few good ways to tweak basic curling movements to make them more productive for you—and to ignite a new jolt of growth. Hit them hard, hit them often, and enjoy the gains that come. Now, get to work!