Any time you want to slow down and drop into your body, as a daily relaxation practice, a wind-down before sleep, or the opening breath before other pranayama or meditation.
Dirga trains a full, unhurried breath in three stages (belly, lower ribs, upper chest) which recruits the diaphragm properly and uses more of the lungs than the shallow chest breathing most people default to under stress. Deep, slow diaphragmatic breathing of this kind engages the vagus nerve, tends to lower heart rate, and shifts the nervous system toward its calmer state, while the step-by-step attention to each region makes it a grounding, almost meditative practice.
Dirga is essentially a structured form of diaphragmatic breathing, which is among the better-supported breathing practices for short-term stress and relaxation; slow, deep breathing reliably calms arousal in the moment. As always, the studies are mostly small and short, so treat it as a dependable relaxation and body-awareness skill and a foundation for other techniques, not a medical intervention.
Dirga (from the Sanskrit dirgha, 'long' or 'complete') refers to the full yogic breath that fills the lungs in three stages. The three-part sequencing taught today (belly, ribs, upper chest) is a modern teaching framework built on classical foundations: the idea of a complete, deep breath runs through hatha yoga, but the tidy three-zone description was refined and popularised by twentieth-century teachers as an accessible introduction to pranayama. It is often the first breathing practice taught in a yoga class for exactly that reason.
Begin lying down with your hands on belly and ribs so you can feel each stage, six to eight slow rounds. As the three-part motion becomes second nature, practice seated, lengthen and smooth the breath, and use Dirga as the foundation you build other pranayama on.
Is this the same as belly breathing?
It builds on it. Diaphragmatic (belly) breathing is the first stage; Dirga adds the rib and upper-chest stages to train a fuller, complete breath.
Should each part take the same amount of time?
Roughly, but don't force it into thirds, aim for one smooth, continuous inhale that simply travels upward through the three regions.
How is it different from Viloma?
Dirga fills the lungs in one unbroken breath; Viloma breaks the inhale (or exhale) into stages with pauses. Dirga teaches fullness, Viloma teaches control.
Safety
Breathwork is a complement to (not a replacement for) professional medical care. If you have a heart, respiratory, or blood-pressure condition, are pregnant, or feel unwell, check with a clinician before practising breath-hold techniques.