With the right plan and the right discipline, you can get seriously shredded in just 28 days.Read article
Close-grip barbell curls target the long (outer) head of the biceps, which makes up the biceps peak.
Wide-grip barbell curls allow you to use more weight and stress the short (inner) head of the biceps more.
VERDICT: CLOSE GRIP
Because most guys want to build their biceps peaks and the long head makes up a good proportion of the biceps mass, your best bet is to focus more on narrow-grip barbell curls — using a grasp that is about hip width or slightly closer.
The best way to build the balance of overall biceps mass is by frequently changing up your hand position for barbell curls between narrow grip, shoulder width and beyond shoulder width. While the narrow grip is great for focusing on the long head for better peak development, the standard shoulder-width grip hits both heads and the wide grip not only hits the short head best, but also allows you to go a bit heavier for placing greater overload on the biceps.