all about the breath
Yoga is much more than the physical postures (Asana) people often think of. Yoga ('to yoke') is a union of mind, body, breath and spirit and both Asana and Pranayama are there to prepare us for the stillness needed for meditation.
Pranayama literally means 'directing the prana' (the energy) and is done through various breathing exercises. Most pranayama exercises are done seated or lying down, but Ujjayi pranayama is the breathing technique used while doing the physical yoga asana.
While doing dynamic vinyasa flow or power yoga, we purposefully link movement with breath; every inhale we move, every exhale we move (either as transition or to go deeper into a pose we are holding). The conscious, audible ujjayi breath helps to focus and create the heat in the body needed for the physical practice. By stimulating the parasympathetic nervous system it relieves stress and by focussing the attention to the present it makes us mindful.
I find it empowering and it makes me feel stronger; I would find it challenging to do push-ups in a gym, but moving through a vinyasa (and moving from high-plank to low plank) using the breath, I can do many of these during a practice. It's moving with the power of the breath.
If the audible breath is difficult at first, perhaps try a mantra; inhale 'So', exhale 'Hum', inhale 'So', exhale 'Hum' (So Hum meaning I'm that) just to help focus on the breath. Try to even out the inhales and exhales, practicing Sama Vritti (equal ratio breathing), evening them out at 4 counts.
How to practice Ujjayi breath
The sound is created by gently constricting the back of the throat to create some resistance to the passage of air. First try inhaling through the nose, then exhaling through the mouth, constricting the back of the throat, creating a 'HA' sound, as if you're trying to fog up a mirror. Then close the mouth and continue inhaling and exhaling through the nose. Gently pulling the breath in on inhalation and gently pushing the breath out on exhalation against this resistance creates a regular soothing sound—something like the sound of ocean waves rolling in and out.
Maintaining a steady, rhythmic breath is the most important part of your yoga practice. By controlling your breath, you calm your mind and bring awareness to the present moment. This awareness is the heart of yoga.
In yoga, it is believed that by consciously practicing breath control exercises, you can bring positive changes to your physical, mental, emotional, and spiritual wellbeing.