If we develop lousy breathing habits through misalignment, damage, or neglect of these functions, we tend not to receive air as well as we could and should. This same air powers our voice, so the verbal communication we vocalise will either flow effortlessly and with ease or become restricted and shallow depending on our breathing quality… 

Certain words get brandished around quite loosely in public speaking domains, and many so-called experts often (in my experience) pinpoint confidence and authority as the two key factors that create an excellent public speaker….