But the best way to train your arms -- or if you even should -- remains hotly debated. The "functional" purists argue that arm training is useless. Then again, plenty of lifters give "bis and tris" their own workout entirely.
While it's definitely true that multi-joint lifts should comprise the bulk of your arm work (presses, pull-ups, rows, dips, etc.), once you've punched the clock with them, it's okay to put in a little bit of overtime for the sleeve-stretchers. Again, just don't let it detract from your bigger, heavier lifts.
For my money, the single-arm barbell curl is the best curl variation. Sure, it smokes the biceps, but it's also a great grip-builder and -- best of all -- teaches the lifter to apply total-body tension to even a small lift.
If you don't lock down the abs and clench the glutes, that barbell is going nowhere.
Don't ego-lift with these. Even if you can easily curl 45-pound dumbbells, the barbell variation will be very challenging. Keep the reps low and the form very strict -- the movement is slow, controlled, and deliberate; and the barbell remains parallel to the floor the entire time. (If a regular 45-pound barbell is too heavy for you, you could either use a smaller EZ curl bar, or just keep hammering your pull-ups until you're ready.)
Try them, and not only will your biceps and forearms grow, but if you apply the total-body tension you learn to other lifts, your overall strength will skyrocket, too.
A few things to note with this video: check out how tight my left arm is locked against my torso. You really want to squeeze that working shoulder down towards your feet without crunching forward. Also, my right shoulder is too elevated. I need to focus on contracting my abs and lats opposite my working side a bit better.