Fish Pose
<iframe src="https://player.vimeo.com/video/195255805" width="640" height="360" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
To do the Fish pose, lie on your back on the ground with your legs together and straight out in front of you. Your arms should be down by your sides.
Then prop yourself up on your forearms and drive your chest up and out. Relax your head back and feel the stretch across your chest and shoulders.