How the three breathing patterns differ
The timer offers three paced breathing techniques, each with a fixed rhythm. 4-7-8 breathing (inhale 4 seconds, hold 7 seconds, exhale 8 seconds) was popularised by Dr Andrew Weil and draws on pranayama, a breath control practice from yoga. Box breathing (4 seconds for each of inhale, hold, exhale and hold) is used by the US Navy SEALs to stay calm under pressure. Coherent breathing, also called resonance breathing, uses an even 5 seconds in and 5 seconds out with no holds, producing a rate of around 6 breaths per minute.
Why paced breathing changes how you feel
Slow, even breathing stimulates the vagus nerve, which carries signals between the brainstem and most internal organs. This shifts the balance from the sympathetic nervous system (fight or flight) towards the parasympathetic system (rest and digest), lowering heart rate and reducing the stress hormone cortisol over repeated sessions. Research on heart rate variability, much of it associated with the HeartMath Institute and researchers Lehrer and Vaschillo, points to a resonance frequency near 6 breaths per minute, close to the pace used in coherent breathing, where the variation between heartbeats is largest and the nervous system settles most efficiently.
When to use each technique
The NHS lists breathing exercises among its self-help advice for stress and anxiety, alongside sleep, exercise, and reducing caffeine and alcohol. 4-7-8 breathing is often used before sleep because the long exhale slows the heart rate. Box breathing suits moments that need quick, controlled focus, before a difficult conversation or a public appearance. Coherent breathing works well as a short daily practice rather than a one-off exercise, since its benefits on heart rate variability build up with regular use.
Technique comparison
| Technique | Pattern | Approximate rate | Typical use |
|---|---|---|---|
| 4-7-8 | 4s in, 7s hold, 8s out | ~3 breaths/min | Before sleep, winding down |
| Box breathing | 4s in, 4s hold, 4s out, 4s hold | ~3.75 breaths/min | Focus under pressure |
| Coherent breathing | 5s in, 5s out | ~6 breaths/min | Daily stress regulation |
This tool is not a medical device and does not diagnose or treat any condition. If you have a diagnosed anxiety disorder, a respiratory condition such as asthma or COPD, or feel dizzy or unwell while practising, stop and seek advice from a doctor or the NHS rather than relying on this timer. Sources: NHS self-help guidance on stress, Lehrer and Vaschillo research on heart rate variability biofeedback.