4-7-8 — Dr. Weil
Inhale through the nose for 4 s, hold 7 s, exhale through the mouth 8 s. A classic for calming down before sleep and easing anxiety.
Box — Navy SEAL
4 s inhale, 4 s hold, 4 s exhale, 4 s hold with empty lungs. An even rhythm for calm and focus under pressure.
Coherent
Inhale and exhale each about 5.5 s, i.e. 5-6 breaths per minute. A frequency linked to better heart rate variability (HRV).
Calm
Inhale 4 s, exhale 6 s. The extended exhale engages the vagus nerve and quickly slows the heart rate.
Sigh — Huberman Lab
Two short inhales through the nose in a row, then one long exhale through the mouth. One of the fastest ways to bring down acute stress.
Diaphragmatic — belly breathing
Inhale 4 s consciously into the belly, a brief 2 s hold, exhale 6 s. Deep breathing that engages the diaphragm, linked to lower cortisol.
Nostril — Nadi Shodhana
Inhale 4 s, hold 4 s, exhale 8 s — a ratio drawn from the yogic alternate-nostril breathing technique.
Lion's breath — Simhasana
Inhale through the nose 4 s, forceful exhale through the mouth 4 s with the tongue stuck out. A quick release valve for tension in the face and jaw.
How to choose a technique
For falling asleep and evening calm, 4-7-8 or Calm work best thanks to the long exhale. For quickly bringing down acute stress, the physiological sigh is the most effective. To stay calm and focused during a demanding task (an exam, an interview, performing under pressure), box breathing is a good fit. You can try all the techniques directly in the exercise and switch between them at any time while it runs.
The scientific background behind each technique — including specific studies — is covered in Breathing articles.