STANDING ONE ARM DUMBBELL PREACHER CURL EXERCISE | ANATOMY OF FITNESS AND BODYBUILDING - 3D ILLUSTRATION | EXERCISE DATABASE & LIBRARY The standing one arm dumbbell preacher curl exercise is an advanced bicep exercise where you turn the dumbbells up and out using a preacher bench to support the triceps and isolate the biceps. Muscles involved: biceps brachill (long and short heads), brachialis, brachioradialis. Target muscles are red.