How to Do the Lying Rear Delt Fly Lie chest facing down, on a flat or incline bench (depending on which muscles you want to target more) with your arms hanging at full stretch, holding a dumbbell ...
'The rear delts (known as the posterior deltoids) are the muscles on the backside of the shoulders,' says Macy Pruett, CPT, a certified personal trainer and the founder of Fittest Core. 'They sit on ...