Surya-Bhedana (Right-nostril breathing)

This refers to an exercise in which one inhales through the right nostril and exhales through the left, holding the inhaled breath as long as possible before exhaling. Although one may eventually develop an ability to do this without using the fingers to close either nostril, beginners, at least, should expect to use their fingers. You may close your nostrils in any way you choose to; but the traditional technique has become standardized as follows. After pressing the index and middle fingers of the right hand against the palm of that hand, use the thumb to close the right nostril and the ring and little fingers to close the left nostril. Left-handed persons may reverse this procedure. When both nostrils are open, the fingers rest on the bridge of the nose.