Stand (torso upright) with a dumbbell in each hand held at arms length. The elbows should be close to the torso and the palms of your hand should be facing your thighs.
While holding the upper arm stationary, curl the right weight as you rotate the palm of the hands until they are facing forward. At this point continue contracting the biceps as you breathe out until your biceps is fully contracted and the dumbbells are at shoulder level. Hold the contracted position for a second as you squeeze the biceps. Tip: Only the forearms should move.
Slowly begin to bring the dumbbell back to the starting position as your breathe in. Tip: Remember to twist the palms back to the starting position (facing your thighs) as you come down.
Repeat the movement with the left hand. This equals one repetition.
Continue alternating in this manner for the recommended amount of repetitions.
There are many possible variations for this movement. For instance, you can perform the exercise sitting down on a bench with or without back support and you can also perform it using both arms at the same time. Additionally, you may perform it with a starting position in which both palms are facing forward. In this case, you may alternate the arms as well, or perform at the same time.
You can also do the exercise starting with both palms of the hands facing the torso and then rotating forward as the movement is performed. At the top of the movement the palms should face forward and the small finger should be higher than the thumb for a peak contraction.