Q.Kapalabhati, the breathing technique recommended for diabetes and asthma, is characterised by:

Kapalabhati is a cleansing pranayama technique defined by its distinctive breathing rhythm, in which one phase of the breath is deliberately active and forceful while the other is left entirely passive. …

What the name tells you

Kapalabhati comes from kapal (skull, forehead) and bhati (shining, illuminating) — "that which makes the skull shine". The name points at its purpose: it is a cleansing practice, clearing the respiratory passages and, in the traditional description, leaving the face and head bright and clear.

The defining rhythm

This is the whole mechanism of the technique, and the whole answer to the question:

• Exhalation — ACTIVE and forceful. The abdominal muscles contract sharply and the navel pulls in towards the spine, pushing a short burst of air out through the nostrils. This is the effort.
• Inhalation — PASSIVE and automatic. The abdominal muscles are simply released. The chest wall springs back, the lungs re-expand on their own, and air flows in without any effort at all.

So the practitioner makes only half the breath cycle. In almost every other pranayama the emphasis sits on a long, controlled inhalation or on retention; Kapalabhati inverts that entirely.

Procedure

1. Sit in a comfortable meditative posture — Padmasana, Sukhasana or Vajrasana — spine erect, hands on the knees.
2. Take a normal breath in.
3. Exhale forcefully and briefly through both nostrils by contracting the abdominal muscles sharply.
4. Relax the abdomen and let the inhalation happen by itself. Do not draw the breath in.
5. Repeat the strokes rhythmically — a beginner may start with about 20–30 strokes to a round.
6. Rest, breathe normally, then take up the next round.

Why it is recommended in asthma and diabetes

• Asthma / respiratory conditions — the forceful exhalations clear the airways of stale air and secretions, exercise the muscles of respiration (especially the diaphragm and abdominals), and increase the efficiency of the lungs. Better control of the out-breath is directly useful to an asthmatic.
• Diabetes — the repeated, vigorous contraction of the abdominal wall massages the pancreas, liver and other abdominal organs, stimulates digestion and metabolism, and helps in reducing abdominal fat. Combined with regular activity and diet, this supports better management of blood sugar.

Refuting the other options

• (a) Slow inhalation through the right nostril only — that is nostril-specific breathing of the Anuloma-Viloma / Surya Bhedana family. Kapalabhati breathes through both nostrils, and its emphasis is on the out-breath, not a slow in-breath.
• (c) Holding the breath for as long as possible — that is kumbhaka, breath retention. Kapalabhati has no long hold; its whole character is rapid, rhythmic strokes. …