I am currently practicing a heavy and fast breathing technique that supposedly boosts immunity by pumping the lymph
I was wondering, considering I have bronchitis at the moment could that further the illness in any way?
If you look at the factors that cause an acute exacerbation of Chronic Obstructive Pulmonary Disease (such as bronchitis), you will find that
The cause can not be identified in one third of the cases. In the ones with identifiable causes, they may be
Respiratory infections (bacterial and viral)
Non adherenace to medications.
When I read through the technique you were talking about, I found that there is no such risk factors in that technique. However, you should take the following precautions:
Avoid this exercise when you have an active acute exacerbation of the disease. Fast breathing causes airways to collapse by Bernoulli's principle, and hence you will have more difficulty breathing. Even though it can potentially clear your airway, it is better avoided at that times.
Make sure that you sit in a place with clean air when you do this exercise. You don't want allergens, toxins or even pathogens in the air entering your lungs when you are breathing like that.
No cold exposure. Cold exposure can trigger a vasovagal attack and can cause constriction of airways. This can even precipitate an acute attack. So a big no no to that.
Even though it is a no brainer, it is important that you monitor yourself all the time. If you feel not so good, stop immediately.
Other than that, it is generally considered a safe practice to do breathing exercises, and are sometimes adviced to patients of bronchitis. If you follow these precautions, you should be fine.