Reverse Fly
How to do:
Grab a pair of 5- 10 pound dumbbells and sit at the end of a chair or weight bench with your feet flat on the floor about hip-width apart. Bend forward at the hips and let your arms hang straight down from your shoulders, palms facing. Raise both arms out to the sides as you squeeze your shoulder blades together. Repeat for 20 reps.
Source: Prevention
