Grasp a pair of dumbbell using a underhand grip (palms facing up) and sit down on the end of a flat bench.

Rest the back of your forearms on the tops of your inner thigh so that your wrists are just off the end of it.

Bending only at the wrists, let the dumbbell drop as far as possible. This is the starting position for the exercise.

Slowly raise the dumbbells up as far as possible squeezing the forearm muscles at the top of the movement.

Pause, and then slowly lower the dumbbell back to the starting position.

Repeat for desired reps.

Exercise Tips:

A light weight should be used with proper technique. It doesn't take heavy weight to make this exercise effective.

Keep the rep timing slow, and pause/squeeze the forearms for a count of two at the top of the movement for added intensity.

Use a full range of motion by allowing the weight to drop as far as possible at the bottom of the movement.