Biceps up, forearms down, one slick rep.
Lower the negative slow with palms down. That descent is where the forearms get hit.
The Zottman curl splits one rep between two muscle groups. You curl up palms up so the biceps handle the lift, then rotate to palms down at the top so the forearms fight the slow lowering phase, where muscles are strongest and most of the growth stimulus lives. It replaces a curl and a reverse curl with a single movement, which makes it one of the most efficient arm exercises you can run.
Lighter than your normal curls, because the palms-down lowering is the limiting factor. Pick a weight you can lower for a slow count every rep, not one you have to drop through the negative.
At the very top of the curl, once the weight is up. Rotate to palms down, lower slowly, then flip back to palms up at the bottom before the next rep. Rotating mid-rep spills the tension.
Zottmans load the forearms harder because the palms-down negative attacks the muscles on top of the forearm directly. Hammers are a strength builder for the neutral grip, Zottmans are the forearm specialist.
