The primary focus of āsana practice is the unity of the body, breath and mind. One way of achieving this unity is through the co-ordination of breath and movement – as the body moves into a position, the mind focuses on the correct breathing, speed and direction for that movement. This integration of body, breath and mind is the purpose of yoga.
In āsana, ideal breathing involves both the chest and the abdomen and moves the spine in ways that enhance each posture. The inhalation begins in the upper chest, which naturally straightens or arches the spine slightly, and continues into the lower part of the lungs. Starting with a gentle contraction of the abdomen, exhalation begins from the bottom of the chest and works upwards.
Ideally, breathing in āsana should be smooth, slow and steady, with awareness, control and sustained attention throughout the series of movements and postures – if your entire being is involved, the movements and postures will have a much greater impact.
The sound and feel of the breath gives important information on what you are doing, For example, a change in the quality of the breath may indicate that you need to rest. The breathing you should use in asana practice is called ujjāyī breathing.