Dumbbells bicep curls are one of the main exercises of many weight lifting routines. It’s an effective strengthening workout for upper arm. Using dumbbells in bicep curls allow you to target you inner bicep muscles significantly. Bicep exercise provides you a greater freedom of movement and a more targeted workout for your arms to have great muscle development. It is important to start with lighter weights as biceps are relatively small muscles that can be developed with lighter weights and there is no particular requirement of heavier weights.