Diaphragmatic breathing.. As in the picture, put one hand on your abdomen, keeping blocked your chest. Inspire expanding your abdomen, then breath out pulling back your abdomen. Repeat ten times.
This exercise enhance your pulmonary capacity and, because it improves your cerebral oxygenation, it is useful to fight psychic stress.
You should carry out this exercise along with thoracic breathing and with the position of relax (SHAVASANA).