As a former opera singer, I know how much breathing affects how a voice sounds. Singers must use deep breathing in order to project a strong voice across a crowded auditorium to reach every single person in the audience.

I never thought that this skill would help me once I left the field of opera – until I had to give my first speech. Then, I realised how much my operatic training made me a powerful public speaker.

Now, having taught public speaking and presentation skills for over a decade, I can say with confidence that the ability to harness your breath is one of the most important, and least taught, areas within public speaking. It's critical when you're speaking up in a meeting, and it's crucial when you're giving a speech or presentation. It's one of the key elements of executive presence.

So how do you harness the power of breathing in order to speak with confidence and power?

Start with the right posture

Stand with your feet shoulder-width apart, weight equally distributed, and raise your arms up over your head. Breathe in deeply. Now as you exhale, slowly lower your arms down to your sides and keep your ribcage where it is. Make sure your shoulders are back, not hunched up behind your ears. This is the best posture for speaking (and singing); you are standing tall, you are owning your full height, and you are resonating confidence.

Breathe deeply

Put one hand on your belly button and one hand on your chest. Breathe in deeply, noticing which hand moves. I see a lot of people breathe while heaving their chest up and down, but I want you to keep your chest steady and think about breathing into your stomach as you take in breath. Then exhale slowly, like letting air out of a balloon.

Having difficulty?

Try “wall sits” – when you lean against a wall with your back flat against the wall and your legs slightly bent. This position helps you focus on your abdomen while breathing, instead of moving your chest. Disclaimer: if you feel light-headed or dizzy, stop this exercise and breathe normally. It shouldn’t hurt – it should simply feel different.

Speak “on the breath”

Once you take in that full breath, you might not know what to do with it. Instead of holding it in, use that breath to support your words, letting it out steadily while you are speaking.

When you speak, practise exhaling slowly while speaking and letting your voice resonate with a full, supported sound. First, practise exhaling while slowly counting: “1.2.3.4.5.” and then practise exhaling on the words, “Hello, my name is [your name].” Practise with a smartphone or a partner. It’s much easier for others to hear the change in your voice than it is for you to hear it yourself.

How often should you breathe? At the very least, at the end of every sentence! If you are prone to rushing through your speech or presentation, then practise breathing at every punctuation mark – it will force you to slow down.

– Copyright Harvard Business Review 2015

Allison Shapira teaches “The Arts of Communication” at the Harvard Kennedy School and is the president of Global Public Speaking LLC, a company that helps people give powerful and authentic speeches and presentations.