Alternating Biceps Curls With Dumbbell

Hold two dumbbells, the arms are streched, the hands are on your side, the palms face inwards. Bend one arm at a time and bring the weight with a fast movement up. At the same time, rotate your arms by 90 degrees at the very beginning of the movement. At the highest point, rotate a little the weights further outwards. Without a pause, bring the arm back down, slowly, and do the same with the other arm.

Don't allow your body to swing during the exercise, all work is done by the biceps, which are the only mucles that should move (pay attention to the elbows).