Stand in front of the weight stack about a foot and a half away and grab the handle with your palms up and arm straight down in front of you. This is your starting position.
Lift the weight up until your forearm is almost completely vertical. Then, lower the weight back down to the original starting position but don't extended your arm straight all the way. You should always keep tension in your biceps for maximum effectiveness. Once you are done performing the entire movement for the desired or prescribed number of repetitions, switch and do the same with the other arm.
Perform this exercise in a smooth and fluid motion
Don't extended your arms completely on the downward portion of the movement
SPECIAL NOTES & LEVEL of DIFFICULTY VARIATIONS
To increase the level of difficulty, slow down the movement or increase the weight.