4·7·8 s
4-7-8
Inhale four. Hold seven. Exhale eight. Long exhale shifts you parasympathetic fast — designed by Andrew Weil for falling asleep.
The protocol
Inhale through the nose for four seconds. Hold the breath in for seven seconds. Exhale through the mouth (lips slightly pursed) for eight seconds. That's one cycle. Do four cycles total in your first week.
The phases are fixed. The technique only works at this ratio — extending the exhale to twice the inhale is the active ingredient. Don't speed up; don't lengthen further than the four cycles in early sessions.
Most people feel a noticeable shift on the second cycle. Some people feel light-headed on the first attempt — that's the parasympathetic response landing harder than expected. Sit or lie down for the first few sessions.
Best for
Falling asleep. Coming down from a panic spike. Pre-bed.
Why it works
The long exhale is the mechanism. When exhalation is significantly longer than inhalation, heart rate drops in the exhale phase via respiratory sinus arrhythmia, and the vagus nerve fires harder. The two-to-one ratio (8 to 4 seconds) is roughly the maximum the body can sustain without distress.
The seven-second hold serves a different purpose: it pauses sensory input, gives the nervous system a beat to settle, and forces the exhale to start from a fully-inflated baseline so the eight-second exit feels complete.
4-7-8 wasn't designed in a laboratory. Andrew Weil, MD adapted it from pranayama and refined it clinically over decades. The mechanism (extended-exhale vagal activation) is well-documented; the specific 4-7-8 ratio is empirical and effective.
When to use it
Falling asleep is the primary use case. Lying in bed, four cycles, lights out. The technique pairs naturally with paradoxical relaxation — let the body slip as the exhale extends.
Also useful in acute panic. The eight-second exhale is hard to fake while panicking; if you can complete one full 4-7-8 cycle, you've already broken the spike.
Not a daily HRV-training tool. The retention phase fragments the resonance window. Use resonance breathing for that.
Or try a different technique