這堂課裡我們學了交換鼻孔呼吸法，這是一個很溫和的呼吸法，不但有清除血液內毒素和排除肺部陳舊空氣的效果，更能平衡及刺激左右腦，調和體內上升和下降的能量流動。它幫助沉澱我們的心、加深我們對內在的覺察力，是一種準備打坐很好的方式。We learned alternate nostril breathing in today's class. It is a gentle breathing technique, with the effect of detoxing our blood and removing stale air from our lungs. It helps to balance our left and right brains and to harmonize the upward and downward energy currents within our body. It is a great preparation for meditation.
呼吸法的目的和其他所有瑜珈練習技巧的目的一致，都是在控制我們的生命力的流動，反轉一般往外追求感官的流向，使其內轉、流向"深層脊椎"－我們的靈性中央氣脈。The purpose of breathing techniques is the same as that of all the other techniques in Yoga practice-to control our life force; to reverse its outward flow towards the senses and to direct it towards our "deep spine", the core of our spiritual existence.
呼吸法的功效是很科學的，其背後的原則就是意識→能量→呼吸→身體的連鎖反應，這個連鎖反應在小孩子的身上最明顯，成人則常在成長過程中學習將其壓抑。比如說，意識接收到好消息時，脊椎內會有一股能量往上衝，上升的能量使我們吸一口氣，所以身體不自覺地挺直、甚至會往上輕輕一躍！The way breathing techniques work is very scientific. The principle that lies behind them is the mind-> energy->breath->body reactive process. This chain reaction is the most obvious in kids, while in adults it gets suppressed due to education. For example, when the mind receives good news, a burst of energy shoots up the spine, which causes inhalation; then the body straightens up and even goes into a leap.
雖然通常較直接外顯的存在層次（身體、呼吸）受著較微妙精細的存在層次（能量、意識）掌控，但其實我們也可以藉由對身體、呼吸的改變，去影響能量、意識層面。Although usually the grosser levels of our existence (body & breath) are controlled by the subtler levels (energy & mind), it works the other way around as well. We can influence our energy and mind by using our body and breath.
藉挺直的坐姿、特定呼吸方式的進行，我們能加強體內的能量流動，而這個流動越強，產生的磁場也愈強，我們的意識以及更多的能量就會不自覺地被吸引往內集中，達到生命力內轉、流入靈性中央氣脈的狀態。By sitting up straight and engaging in specific ways of breathing, we can increase the energy flow within our body. The bigger the flow is, the stronger the magnetism it creates. Our consciousness and more energy will then naturally be attracted inwards. So the state of withdrawing our life force into the core of our spiritual existence is achieved.
如同Swami Kriyananda 在【瑜珈的藝術與科學】所說：
As Swami Kriyananda wrote in Art and Science of Yoga:
"After practicing the breathing exercises, go into inner stillness. Feel the connection between your breath and the Cosmic Breath, as if your breath were but a function of the breezes of cosmic consciousness. In your breathing, as in your working, feel that you are an instrument of the Divine"