Q: What is the physiology behind the deep breathing biofeedback exercises? Is it the breathing stimulates the corotid chemorecetors registering an increase in O2 levels kicking in the parasympathetics to relax the smooth muscles in the arterial walls?
A: Resperate use can be viewed as a deep breathing exercise. Extensive scientific studies have been done on how it works to lowers high blood pressure. The slow breathing achieved with the Resperate decreases sympathetic nerve activity which leads to relaxing of blood vessels. This response is triggered by mechanoreceptors in the lungs and heart. To read a more complete overview on how Resperate works go to this Clinical Overview on the device.
For information about other deep breathing exercise programs, I suggest you ask the program you are using to provide their scientific studies .