If any of you guys out there (or girls -- I apologize for being so presumptuous) want arms shaped like pythons that swallowed a pig, then you need to make sure you're using proper lifting form. Since bicep curls are a favorite arm exercise among lifters, we'll start with one of the best moves you can do: the barbell curl.

Holding a barbell, start with your hands at around shoulder-width apart, palms facing up. Then, lower the bar until it is just in front of your thighs. Be sure to keep your elbows tucked in tightly against your body, as allowing them to flare out will place too much stress on your wrists. Keeping your back straight and abs drawn in, curl the bar up in a semi-circular motion until your forearms touch your biceps. Throughout the motion, be sure to keep your head facing forward. Tilting it down or to the side to look at your biceps can not only strain your neck muscles, but it will also make you look like kind of a tool for admiring yourself (besides, that's what the mirrors are there for).

The barbell curl is a great way to give you strong and dense biceps. However, it's worth knowing that the size of your arms actually has more to do with your triceps than it does your biceps. So, for maximum results, be sure to also incorporate such moves as push-downs, dips, and skull crushers into your arm workouts.