Dumbbell Floor Flye by Men's Fitness Editors March 1, 2017 1.46pm Type Strength Training Equipment Dumbbells Body Parts Pecs Photo credits: Top, James Michelfelder; Step 1, James Michelfelder. Step-by-step instructions 1. Lie on the floor with two dumbbells above your shoulders. 2. With palms facing each other, lower the weights in an arching motion until your elbow hits the ground. Then, squeeze the dumbbells back together in an arching motion. That's one rep.