When I was living and acting professionally in New York, I took a course on meditation at the Himalayan Institute. Casually one day, the teacher expressed an opinion that has stayed in my mind ever since.

“We don't have an epidemic of heart disease in this country,” he said. “We have an epidemic of breathing disease.”

You could call that a “breathtaking” statement in itself. It certainly resonated with someone for whom — as a stage actor — breathing and breath control were central to my art.

What the teacher was saying was that a typical person's heart isn't given enough oxygen because of poor breathing habits. A heart continually deprived of an adequate supply of oxygen will naturally fare poorly over time. Interestingly, the same careless breathing habits will negatively affect your performance as a public speaker.

Why? Well, an interesting fact about public speaking is that breathing for speech is different from breathing for life. The latter is sometimes known as “vegetative breathing,” meaning that it is passive and not aimed consciously at a goal. In speech, however, breath not only is the energizing force which powers our vocal folds. It must also be controlled to achieve the effects a speaker desires. Chief among these is sustainingthe sound, since in English the most important words — the ones that need to be “punched” — usually come at the end of a phrase or sentence.

This means that as speakers, we use controlled exhalation that is much longer than the “quick in and out” inhalation-exhalation cycle of breathing for life. We must control our exhalation, and that means taking full breaths that form the reservoir of air that powers our speech.

Speakers therefore must breathe more deeply than in everyday vegetative breathing. This is often a particular challenge in public speaking, when self-consciousness and adrenaline are enticing us to breathe shallowly and rapidly.

Getting a full reservoir of air that allows us to sustain our vocalization is only one benefit to slower, deeper, relaxed breathing for speech. A full rush of air that fills our lungs actually slows our heart down, calming and centering us. Try this exercise yourself: Get a baseline pulse rate at your wrist, then take a huge intake of air, pause for a few seconds, then “whoosh” it all out in a big exhalation. You should feel a distinct slowing on your pulse rate in the first few seconds afterwards.

Another reason to breathe fully and deeply is that it oxygenates our brain. And the brain needs this precious fuel oxygen if it is to function at top efficiency. In the speech environment where thinking on one's feet is paramount, this is no small benefit.

So, try some relaxation exercises — lying down or sitting, it really doesn't matter — that teach you to breathe slowly and more deeply. You'll feel good, and you’ll be more centered and ready to speak. Equally important, you’ll look good by avoiding a “caved in” appearance. Best of all, you’ll be able to vocally support your crucial points as you talk.

One other suggestion: As you do your relaxed breathing exercise, try to get your inhalation and exhalation to be continuous. That is, there should be no starting or stopping point where the inhalation ends and the exhalation begins, and vice versa. Think of your breathing rhythm as a figure “8” on its side, which is actually the symbol for infinity: there is no break anywhere. Unobstructed breathing like that helps loosen the mental blockages that are so often part of our trepidation about speaking in public.

All in all, not a bad package of benefits from the simple art of learning to breathe properly, is it?