The lap barbell curl is a great exercise for increasing force production in the biceps as well as for hypertrophy (growth).

Lap Curl
  1. Sit down and place a barbell on your lap.
  2. Place your hands just outside of your lap and squeeze the bar as hard as possible.
  3. Explode with great starting force into a curl, ending with the bar at your chin or throat. Try not to knock yourself out.
  4. Bring the bar back down to your lap and repeat.

Sets of 8-12 work great with this exercise. You can also take things up a notch and do 3-6 reps per set.

The most important part of the movement is the initial explosion. Fire the bar off the lap to forcefully contract the biceps. Drive is the most important part of this exercise. Starting force must be explosive and it must continue until you've completed the range of motion. Squeeze at the top of the contraction. Bring the weight down under control or get comfortable with bruised thighs.

Related:  The Cure for Puny Arms

Related:  The Best Biceps Exercises You're Not Doing