When is the last time you thought about your breath? Unless you're an athlete or a doctor, probably not recently. We've been breathing since the moment we were born, and it's just something that happens. Like the sun sets and rises, we breathe. So it's something we shouldn't really have to think about, right?

Guess again.

Many of us have grown into adulthood breathing in the same way we did when we came out of the womb. We breathe slowly when we are calm and relaxed and we breathe faster when under stress or engaging in strenuous physical activity. This is normal. But how we breathe makes a big difference in posture and spinal extension, which is something we don't often give enough thought to.

As a yogi, I often think of my breath, and I often forget to think of my breath, too. When I am practicing, my breathing is very deliberate; I evenly inhale, drawing breath in through my nose, along the back of the throat and into my chest and abdomen – filling the chest first and then the abdomen. With each breath I imagine my spine lengthening and extending, creating space between each vertebra. At the end of my practice, I have found new length in my spine and I feel a little taller.

Sometimes, when I am outside of my practice, I forget to take note of the quality of my breathing. My breathing becomes shallow and too much in the chest. I know from my decade of experience as a health and fitness teacher that shallow chest-breathing leads to shortened pectoral muscles, shoulders that pull forward, and a slightly hunched appearance. This is because when you breath into just the chest or just the abdomen you inhibit full spinal extension and the spine can begin to curve. Ultimately this can lead to poor posture, spinal misalignment, and back pain.

Try this visualization exercise, which will help you improve the quality of your breath: Sit in a comfortable cross-legged position on the floor. Rest your hands in your lap or on your knees and close your eyes. Begin to inhale slowly through the nose and exhale slowly through the nose, guiding the breath along the back of the throat. With each inhale and exhale begin to deepen the breath. Now, on your next inhale, consciously fill the chest with air first and then fill the belly. You needn't fill them too much, just so it feels natural. Now exhale in the opposite way, contracting the abdomen and pulling the belly button in towards the spine as you empty the air upwards from abdomen, to chest, to nose. As you do this, imagine your spine growing longer with each exhalation. With each inhalation, reach the crown of your head towards the ceiling, lifting the upper body up out of the hips. Visualize your spine lengthening and extending, each vertebra separating from its neighbor, the ribs expanding to make room for the heart, the belly growing more fluid and supple.

You will notice with this new breath that you feel more relaxed, maybe your tense muscles have loosened, your spine feels more comfortable. Take this feeling with you when you finish the exercise and remind your body how to grow and extend with your breath throughout your day. Every once in a while, remind yourself to breathe into both the chest and abdomen, filling the chest first and then the belly. Stand tall and pull your shoulders back, extend out of your hips. After a while, you might find that quality breathing becomes more natural, a new habit. We can't control much in this life, but we can at least take control of our own breath, making it the best breath it can be.