What is the best curling machine for developing the biceps?

Q: What is the best curling machine for developing the biceps?

A: If you had asked Nautilus inventor Author Jones that question when he was alive, he would have said the Compound Position Curl Machine, a contraption he invented. Jones believed the only way to achieve full contraction of the biceps was with the hand supinated—palm up—with the forearm “bent back as far as possible against the upper arm” and the upper arm “raised in relation to the torso.” So he designed a machine that enabled the user to do just that—however, it wasn’t very popular, and he discontinued production of it.

I agree with Jones in a lot of areas, but his obsession with trying to find a single-best exercise for every muscle doesn’t fly. To work all the motor unit pools of a muscle, you need to train the muscles from a variety of different angles. For example, an incline dumbbell curl is great for emphasizing the long head of the biceps, and the prone one-arm incline curl effectively works the short head of the biceps.

If you get the opportunity to visit the Poliquin Strength Institute, you’ll see that I have a wide variety of machines for training the biceps. I have machines with selectorized weight stacks attached to pulley systems and machines that work on leverage. Regarding which is best,  I would say, “The one you’re not using.” Again, variety is key for developing the maximum number of motor units that influence growth.