To further add after you get the breathing animation the way you want then go to each frame and export the figure as an object.  You have to make sure to export a single frame at a time.  This will make a series of objects that each are different and have your breathing movements.  

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13