Supinating Hammer Curls
If you've noticed, the bicep is most peaked when your hands are supinated (palms facing up) when doing standing Dumbbell Curls.
This variation of the hammer curl takes it to the next level. You're not only twisting the wrist to get the bicep to contract fully, but you're also pausing the weight in a contracted position. More time under tension!
Notice how I'm also flexing the tricep at the bottom of the motion. This keeps your from cheating the rep and gives you full range of motion!