Nadi shodhana

The name means cleansing of the channels. Sitting upright, you use the thumb and ring finger of one hand to close alternate nostrils: inhale left, close left and exhale right, inhale right, close right and exhale left — that is one round. Breathing stays slow and silent, and the counts are usually equal to begin with. Five minutes is a full practice.

What it is for is a reliable shift towards calm and a noticeable settling of attention. Because the pattern requires counting and a small hand movement, it is harder to do absent-mindedly than plain deep breathing, which is part of why people find it works. Small clinical studies have reported modest reductions in blood pressure and improved attention scores after slow alternate nostril breathing; the effect you can verify yourself is that the mind is quieter at minute four than it was at minute one.

In a KEO session this is the breath practice most often used before a long stillness or at the start of an evening class, and it is the one Ben recommends taking home: it needs no mat, no space, and no one to teach it after the first time. Two cautions, both plain — stop if you feel light-headed, and skip it if your nose is blocked, because forcing it is pointless.