Arms are one body part that, when sufficiently developed and defined, just scream right away, “Yes, I train my ass off!” The Behind-The-Back Cable Curl is another great way to better emphasize the long head of the biceps to build that biceps peak.
There’s not a guy alive who isn’t interested in a more impressive biceps peak. And while the amount of peak you have on your biceps is genetically predetermined to an extent, that doesn’t mean you can’t drastically improve what you’ve got. The key is proper exercise selection. The majority of the peak that pops up when you flex your biceps is made up of the biceps’ long (outer) head. And although both the long head and short (inner) head work together to flex the arm, you can place better emphasis on the long head with the right techniques.