bicep exercises

[C-RaD]

ive heard about this one exercise where you get dumbells and hold your arm at a 90 degree angle until you can no longer hold your arm up. should you do this when your doing normal arm curls where your palms facing up or with hammer curls? or does it matter?

 

[Nobody]

Well, I'd say the regular bicep curl is more effective, don't really know how this works, however.... ''