Matsyasana, or fish pose, is traditionally known as the destroyer of all disease, and I mean, who are we to argue with that? I usually do this as a counterpose to shoulder stand, and breathe in it for at least 10 breaths. Benefits include a good stretch in the stomach, deep hip flexor muscles and the muscles between the ribs. Unless you're familiar with getting in and out of the pose, look for a full guide on how to do it first (I'll post one soon), as there is potential for neck and low back injuries.