With this move, you'll be switching up your bicep-curl underhand grip for a neutral grip, where your palms face each other. It's a great isolation move, which means it tackles one specific muscle ...

A study found that keeping the wrist neutral - like the neutral grip used in a hammer curl - decreased wrist muscle activity ...

The only problem is that constant bicep curls can get a little ... This is due to holding the pair of dumbbells with a neutral grip (palms facing each other). It will therefore work your forearms ...