<iframe src="https://player.vimeo.com/video/277210483?background=1" width="640" height="360" frameborder="0" allowfullscreen></iframe>
Using two dumbbells, start with both arms by your sides with palms facing towards your body. Raise both arms up and out in front of you to 90 degrees then back down, then lift straight out to the sides to 90 degrees then back down. Keep repeating front to side raises.