There are many who are critical of attempting to change diaphragmatic breathing patterns simply because we don’t have much evidence that they exist, as I do fall into that category I seek to demonstrate that we are actually changing something. One repeated statement I’ve heard recently is that “if we don’t have spirometry measures to show the effectiveness of the protocol, how do we know it’s working.” Unfortunately, I’m not wholly convinced that the argument is as effective as it could be and leaves me with the question that we must answer, what, exactly are we trying to change with diaphragmatic breathing training?
I can say assertively that I don’t think we’re changing anything valuable from a perspective that is measurable via spirometry. Spirometry simply measures volumes and velocities of air moved by the lungs. Unless we’re talking about diaphragmatic breathing training for those suffering from COPD, we’ll have a pretty difficult time changing lung volume, though resisted training may lead to improved velocities in inspiration and expiration.
If we are going to measure respiratory gasses relating to breathing dysfunction, we need to be more specific than simply “air,” and must look at the components of expired air. To this end, capnography reigns far supreme to spirometry as it can tell us the air’s contents of CO2, a vital player in breathing drive. In individuals who are “over-breathers,” the big issue is often respiratory alkalosis from exhaling too much CO2 and become oxygen drunk, which drives the pH of the body up as CO2 cannot disassociate and form carbonic acid. What we get in this case, then, is some funky responses. Those with diaphragmatic breathing dysfunction forced into hypocapnia run into a number of pitfalls including smooth muscle constriction (bear in mind that many connective tissues have some smooth muscle fibers), the Bohr effect takes place facilitating greater ischemia and increased risk of trigger point evolution, and the sympathetic nervous system kicks into overdrive with more rapid reflex arcs, decreased pain threshold (and long term hyperalgesia), and altered balance. Couple this with the body’s drive for maintained homeostasis, thus the kidneys begin to pump out more bicarbonate, leading to disturbed calcium and magnesium balances, a perceived “normal” blood pH, and increased anxiety and we have a vicious, self-perpetuating issue.
Normal breathers should take between 10 and 14,000 breaths per day, however, over breathers do a lot more, slightly smaller “reps” but the gas exchange is not proportionally small enough, forcing too much CO2 to go visit the trees. Ideally with retraining of a good diaphragmatic breathing pattern, we can begin to normalize the amount of CO2 within the system by slowing down breathing and resetting the brain’s perception of “normal” blood gas levels.
Using capnography biofeedback may be an excellent tool in retraining and can help answer the all-important question “is it working”, however, the machines are impractical. Thus, I defer to the “common sense” and “supported by literature” ideas of Charlie Weingroff’s evidence informed practice beliefs. In 2008 McLaughlin and Goldsmith demonstrated that, in an average of 5 sessions including diaphragmatic breathing training, subjects were able to improve respiratory chemistry (measured by capnography) and gain increased function. While it’s only a single piece of literature, it does provide me with enough support to believe that I’m not walking sheep.