Box breathing, a free breathing practice slowing the breath into four equal parts, is used as a quick, on-demand stress tool. Small trials show short-term drops in anxiety and stress; patterns stretching the exhale often do as well or better. Mood, sleep, and blood-pressure claims rest on mixed or indirect findings, aging claims on reasoning alone. Risks are small; long holds in water or while driving are dangerous. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Resting heart rate | 50–65 beats per minute | Tracks overall calming |
| Home blood pressure | Below 120/80 mmHg, ideally near 110/70 | Detects additive lowering or benefit |
| HRV (RMSSD) | No established target; track change from own baseline | Gauges calming-branch activity |
| GAD-7 score | 0–4 | Tracks anxiety symptoms |
| Perceived Stress Scale (PSS-10) | No established target; lower than own baseline | Tracks perceived stress |
| Insomnia Severity Index | 0–7 | Tracks sleep benefit |
| Resting breathing rate | No established target; downward change from baseline | Reflects breathing retraining |
| Slow-exhale test | No established target; longer than own baseline | Sets and progresses hold length |
| Session anxiety rating | 0–10 scale, rated before and after each session | Checks single-session effects |
Cadence: Baseline week before starting; questionnaires and resting measures at 2 and 4 weeks, then every 3 months while practice continues; anxiety rated before and after each session for the first 2 weeks; people taking blood-pressure medication add readings during the first 2 weeks.