Start: Grab a pair of light dumbbells and sit with your legs together on the front edge of a bench. Lean forward at the hips to get your chest as close to your thighs as you can without rounding your back. Let your arms hand down from your sides in line with your calves as you hold the dumbbells with a underhand grip.
Finish: Use your rear delts and upper-back muscles to raise the dumbbells up to either side in a wide, arcing motion until your arms are parallel to the floor, your elbows just below shoulder level and your wrists in the same plane as your ears.