Physiological Sigh Timer

The fastest known method to reduce stress in real time.

Breathe In3

What is the Physiological Sigh?

The physiological sigh is a natural breathing pattern — you do it involuntarily before crying, when transitioning out of sleep, and during emotional stress. It consists of a double inhale through the nose (a full breath followed by a short 'top-up' sip of air) and then an extended exhale through the mouth. Neuroscientist Andrew Huberman popularised the deliberate use of this pattern after Stanford research showed it is the most effective real-time method for reducing physiological arousal.

Why Double Inhale?

The double inhale maximally inflates the alveoli (tiny air sacs in the lungs), many of which collapse during shallow breathing. Reinflating them maximises the surface area for carbon dioxide offloading on the subsequent exhale. The extended exhale then strongly activates the vagus nerve, slowing heart rate and reducing sympathetic activation. This one-two punch is why a single physiological sigh can be felt immediately — it's not a gradual calming technique.

How to Use This Timer

The timer guides you through 3 cycles: inhale (3s), brief hold to allow the 'sip' (1s), then a long exhale (6s). Three cycles takes about 30 seconds and is typically sufficient for acute stress relief. For ongoing anxiety, repeat sets of 3 with brief pauses between them. This technique is ideal for use before a presentation, after receiving bad news, or any moment you need to calm down quickly.

Frequently Asked Questions

How many physiological sighs should I do?

1-3 sighs is typically enough for immediate calming. The 2023 Stanford study found that 5 minutes of cyclic physiological sighing daily produced greater positive mood improvements than equivalent time spent on mindfulness meditation.

Is the physiological sigh the same as a deep breath?

No. A single deep breath is one continuous inhale. The physiological sigh is specifically a double inhale — a full breath followed by an additional short inhalation — then a long exhale. The double inhale reinflates collapsed alveoli, which is the mechanism that makes it more effective than a standard deep breath.

Other Breathing Techniques

Box Breathing Timer Equal inhale, hold, exhale, hold — the tactical breathing protocol. 4-7-8 Breathing Timer Dr. Weil's 'natural tranquilliser for the nervous system.' Resonance Breathing Timer 5.5 breaths per minute — the frequency that optimises your HRV. Wim Hof Breathing Timer Power breathe. Hold. Recover. Repeat.