[header] How to do bicep curls [title] Start small and work your way up the dumbbell scale as you progress. [step] If you are new to doing curls, or simply looking to maintain existing muscle tone, even 1 to 3 lb (0.45 to 1.36 kg) weights may be sufficient. Taking on too much weight causes a breakdown in technique and can easily lead to injuries of the elbow, wrist, or muscle tissue. 
[substeps] If you are going to do 2-handed curls with a bar, the same principle holds. Start at a lower weight and work your way up slowly.