1. This movement is performed with dumbbells.
2. Stand with your feet shoulder width apart and slightly bent to relieve stress from your lower back.
3. Grasp ech dumbbell with an underhand grip, as well keep your thumbs under the grip rather than over top. Begin with the dumbbells hanging straight down at your sides. Now, keeping your elbows in at your sides and stationary, curl one dumbbell straight up in front of you. Do not swing up the weight. Pause and flex your biceps hard at the top of the movement.
4. Simultaneously lower the dumbbell back down to a fully extended starting position while curling up the other dumbbell. Repeat the movement.

This is a great movement for overall biceps developement, it is a must for basic compound development of the biceps. Performing this exercise with dumbbells rather than a barbell allows you to isolate each biceps. It also minimizes the cheating since you you can concentrate at one arm at a time. It is also very effective once heavy weights are used to add thick mass to your biceps. Keep your elbows in one place close to your sides at all times and flex hard at the top! Another tip is to keep your wrists locked out straight, this will further isolate the biceps. Good Luck!