The offset grip dumbbell curl is a very useful variation on the standard dumbbell curl which shifts the weight as you exercise your biceps. Grab a set of dumbbells holding one in each arm and letting them hang down by your side. Rather than hold the dumbbell in the centre, hold to one side which will shift the weight and vary the exercise. As you lift the dumbbells up towards your shoulders, only moving your elbow, slowly open up the palms and then hold at the top of the cycle. Then slowly lower the dumbbells back to the starting position by your side.